My question is: My house was built in 1902 and I have a wood
burning fireplace that was redone at some point and the facade goes up to the ceiling. It's very pretty but the shape gives me the impression that there is still a mantle behind the built
up wall around it. It also sounds solid up to that point when I knock on it then hollow past that point. My fear is that there isn't one;then what? and there is an arched shelf nook
in the face of the fireplace wall with a shelf that comes out and there is actually a working out let under it, like inside the fireplace facade. What the heck? It is stuffed under the shelf with old, old newspapers and a tiny bit of insulation. But the outlet is messing my brain up. I'm not sure why that would be there and what am I going to run across if I knock down the fake part. Any clues?

if you drill a half inch or 3/4 inch hole and insert a fiber-optic inspection camera (a cheap one for $80 at Harbor Freight does the same job as a $300 Milwaukee), you can answer some of those questions yourself.

I suspect some idjit wanted a sleek wall look at some point. Nicole Curtis would have chased him/her/it with a chunk of salvage lumber for that.