we're doing renovations
I was trying to clean some plaster that was next to a power outlet and I used the same metal "thing" used to spread the plaster on the wall. (it's a thin metal blade) the plaster broke and the metal blade went in the power outlet area and touched the hot screw, making some spectacular sparks and basically destroying (vaporising) a small piece of the metal blade.
the breaker did not trip. the whole thing only lasted a fraction of a second. also, the blade only touched the black wire screw (hot) and did not short hot with neutral or ground. the screw that holds the black wire is not melted, just black on one side
#1 why would there be sparks if there was no short? I don't think the blade touched the box of the outlet because the box is deeper inside the wall. the blade was touching the wall. is the wall acting as a ground?
#2 I opened the outlet. all the wires in the house are new. I looked at the wires for the hot, neutral and ground and all look fine, no melting and no marks whatsoever. the plastic insulation is the same way it was the day the wires were installed. the only evidence that this happened is on the screw that holds the wire in the outlet. I still have power to the circuit. could this have caused any permanent or serious damage to the wires inside the wall?