Check the insulation on the wires as far back as you can to see if it is brittle and crumbling. We bought a house where the previous owner put a an over-wattage bulb in a ceiling fixture. As I carefully pulled the fixture down to replace it, all of the insulation on the wires above flaked off leaving bare copper wires. The heat had cooked the insulation to the point that it was brittle and crumbled off as the wires were disturbed.

 

And my solution for toasted insulation is to slide plastic drinking straws or fishtank air hose or shrink tubing as far in as needed, if you decide to adopt such, instead of breaking walls to replace bad wires...

 

Hello, good folks:

Yesterday I had occasion to troubleshoot three bedroom electricity that all of a sudden went out. I got lucky and started opening outlets and found the one pictured below. The question is, how in the world did this ever get fried?

It’s actually new home owners (about a month) who only used a nightlight plugged in there. The outlet is extremely old so perhaps the previous owner did something or perhaps just old age?

I also found the outlet at the hot wiring was extremely hot to the touch when I opened it most likely from the extremely high resistance of the hot, frayed wires.

Anyway, I replace the outlet and everything works great. But I’m just curious what my cause this.

The outlet was destroyed because of heat from a high resistance connection. This often is due to improper wire connections where there would be a large current passing through the connections to the outlet. A much better method is to properly splice the wires with a wire-nut, adding another short wire to connect to the outlet. BUT note that the wire-nut must be large enough to make a good connection among all of the wires.