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Sizzling light switch

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Mar 23, 2013, 09:53 PM
Sizzling light switch
The light switch in a room used for storage sometimes sizzles when I turn it on. Sometimes the sizzling continues, sometimes it stops after a minute or so.

It's not a loud sizzle and usually can't be heard unless I put my ear close to the switch plate. Still, it's a scary sizzle.

I've googled the subject and confirmed what I suspected - that it's a fire hazard and that the switch needs to be replaced, but the info I found suggested that there may be wires other than just the switch wires that could be bad.

If I change the switch and there's still sizzling, does that infer the problem is greater than the switch and in the wires? If so, how can I determine how extensive the problem is? Since the room is used for storage and is pretty full, any access to anything other than the light switch would be problematic.

On the other hand, I don't want to wait until I can clear the room out to get the problem fixed.

I assume the fire hazard continues to exist even if I don't turn the light switch on?

Any other observations or suggestions anyone can share?

(The house was built in 1950, still has fuses, and none of the wiring in this room has been updated since I bought the house in 1978.)

Thanks for any suggestions and comments.

This message has been edited. Last edited by: GardenSprite,
Mar 23, 2013, 11:50 PM
Odds of it being a defective switch - Pretty close to 100%

Odds of it being a poor contact at a splice within the switch box - possible but not too likely

Odds of it being contained within the wiring that is behind the walls - About the same as OJ being innocent.

Take the simple approach - replace the switch. Almost certainly this will solve the problem (which is probably burnt contacts inside the switch). If you replace the switch and still hear the sizzling, then simply check any wire nut connections inside the same switch box. If the problem continues then it's time to call in a pro - but I will be REALLY surprised if this goes beyond a simple switch replacement.

Mar 24, 2013, 10:43 AM
JayBee, thanks so much for responding so quickly.

I will change out the light switch first as you suggested.

Now, I have to reveal my limited lack of knowledge about there anything special I should look for when getting a new switch? I haven't changed one in years but I recall seeing something about switches for houses with aluminum wiring. I have no idea if my house has aluminum wiring or how to tell.

Other than that, I'll just get a switch from HD or Lowe's, right?

Thanks again for your help. I can deal with most house problems but electrical ones scare me.
Mar 24, 2013, 11:20 AM
You should find what you need at any big box store.

Biggest thing will be if it's a two-way switch (only one switch controls the device) or a three-way switch (two switches control the device. You can tell by checking the outside as the switch toggle will be marked 'on' or 'off' for a two way. There will be no markings for a three-way switch. You can also tell once you open the switchbox up - a two-way will will have two contact points and maybe a ground while a three-way will have three contact points and maybe a ground.

So, turn off the breaker that controls the switch, take off the cover plate and remove the switch. Even if the wires are old, just scrape the ends of one wire - it will be copper colored if copper, silver colored if aluminum. If it's aluminum, just get a switch that is made for aluminum. It will cost a bit more. A regular copper switch in two-way is about 69 cents.

Replacing the two-way is easy - take off the old switch, install the new by connecting the two wires to the two contacts. Impossible to get it wrong.

A three-way is more complex. While it will have two terminals on one side and one on the other, different brands will be set up differently. Look for one terminal on the switch that is a different color - usually black. Make sure that the wire that is on the black screw on the old switch goes to the black screw on the new. Then take the wire that is directly across from the black screw and put it in the same place on the new. Test the three-way before fully installing it. Try all the combinations of flipping both switches. If it doesn't work correctly, first try reversing the two wires that are on the non-black terminals. If it still doesn't work correctly, write back and I'll talk you thorough it.

Mar 24, 2013, 12:28 PM
One other thing you can do to isolate the problem [but takes more work] is if you take the "sizzling switch" and re-install it into another "good sounding switch", and vice-versa.

If the bad sounding switch does the same thing in another good working switch box, then it is most likely the switch for sure, more so if the good switch from the good box is installed into the bad switches box and works fine.

Finally, when it comes to safety, never let a full room of boxes thwart your work-ethic to appropriately determine any real potential problem. Having a bunch of boxes to move is much better than having no house to move a bunch of boxes...

More than likely it is a bad switch, but the process above will tell you for sure. And as Jaybee said, always turn-off the appropriate breaker(s) b4 you ever begin...

good luck,
Mar 25, 2013, 04:18 PM
Jaybee, thanks again for your help and offer of assistance. I REALLY did feel more comfortable knowing that such help was available.

Thankfully, the problem is solved.

The switch did have copper wires, and is a two-way switch, so that made it cheaper and easier.

When I removed the plate, I found that the screw holding the wire on the right side (of this old plate with wires connecting to both sides) was quite loose. The screw on the left was a bit loose as well, but not as much as the right side screw.

I also discovered that the wire on that same side was touching the plastic box on the back of the switch.

In addition, the screw holding the box in at the bottom was so loose it was almost out. The top screw was loose as well but not nearly falling out.

I tightened the screws, gently moved the wire away from the plastic, put it all back together and no more sizzling. Cool

The only remaining issues are a concern and a puzzle. The concern is that the right wire had at one time been covered with that black stuff (coating?) but it had worn almost off, showing the gold underneath. But the wire wasn't bare, just shorn of its black overcoat. Is this an issue? Should I have that wire replaced?

The puzzle is how all the screws became loose. I wouldn't think there's any stress on them, there was no sign of chewing (i.e., mice or other pests), but I guess I'll never know.

The only loose screws I have to worry about now are those in my head. Roll Eyes

TsTex, I had initially decided to use your test method, and would have done so had the loose screws not solved the problem. I appreciate that suggestion, and it would have been easier as the other rooms covered by that particular fuse at least had good ambient light, whereas the storage room didn't. That was one of my biggest worries - how to work on the switch in such a dark room, but the lights I hooked up from an area with power provided enough to see all right.

I also appreciated the reminder that safety is more important than worrying about the appearance of the house. For reasons I've never understood, we women seem to fuss about things like that when in the long run they're not that important.

I also learned that years ago my father made a test box for lights and switches, which I could have used on the switch had the loose screws not solved the problem.

Thanks VERY MUCH to both of you for helping me with this problem.
Mar 25, 2013, 06:05 PM
You need to be on the lookout for a mouse with an itty-bitty screwdriver. Smile

Electric current can cause some normal vibration. This could cause the screws to come out. Usually, for this to happen, the screws weren't tightened very well. But, they can eventually loosen up buy themselves. Or the mouse thing. Maybe.

Hard to make a call on the loss of wire insulation. Old wires will eventually get brittle and the insulation will crack off. The problem should be worse if the wire is moved - like what you did to fix the switch. Moving the brittle wires would cause the insulation to crack off. It's a safe bet that the wires contained within the walls that do not move are in better shape than the ends of the wire that are bent around inside the box with the switch. Still, this is one of those things that may be worth having a pro check out.

Mar 25, 2013, 10:48 PM
Jaybee, thanks again for the info.

I have a couple other electrical projects that aren't DIY caliber (ceiling fixture needs replacement) so I'll call an electrician for them and to check out the wire with lost insulation. The wire was very, very stiff, so I was very careful with it.

Is this a fire hazard? I'm wondering whether I should get this done ASAP or wait until the tax refund comes Confused?

Maybe the electrician will find the meddling mouse too. Big Grin Perhaps it needs a lecture on minding its own business and sticking to stealing cheese.

Thanks again. It's comforting to know that your reliable advice is available.

Further thoughts...would wrapping the wire in electrical tape offer any safety protection, temporarily?

This message has been edited. Last edited by: GardenSprite,
Mar 26, 2013, 05:48 PM
You know, replacing a ceiling fixture is not too heavy duty. Usually a good DIY type project.

Wrapping the suspect wire in electrical tape can only help. A nice, clean tape wrap will work as well as the wire insulation.

Mar 27, 2013, 10:25 PM
Wrapping I can do!

Thanks again for your guidance.