I was installing an in-wall oven at a rental property but got interrupted and had to come back the next day. The house is old and only has a 3 wire circuit -- no ground. The oven's manufacturer said to wire nut the oven's ground wire to the neutral. While I was gone, my tenant decided (against my instructions) to wire it himself, and briefly nutted the house's red and white wires together. When he turned the breaker back on, he smelled melting plastic, and turned the breaker back off. I rewired it correctly, but could still smell a faint "melted plastic" smell when I turned the breaker on. So I turned the breaker off again. How can I tell if the wiring is safe? (The oven lights up correctly now when the breaker is turned on.) Thanks!

My entire unfinished basement has been rewired. The electrician installed a 3 way light switch at the top and at the bottom of the interior stairs. However, there is no light switch installed at the exterior entry door. If entering the basement from outside you have to find your way in the dark to the bottom of the interior stairs to switch on lights. I mentioned this to the GC and he said that the switches installed were code and there is no switch required for the outside entry. Is this correct? It seems that a 3 way switch at both points of entry (interior and exterior) would be the code requirement.