Hot Wire

I gave myself a B+ for my new conduit installed between the ceiling light and my junction box where I was putting a smoke detector. Notice the nice offsets. I only got a B+ because after installing the wires, it occurred to me this is a switched light and I needed constant power. So it would have been an F except for the fact whoever wired the ceiling light wired the switch with the common wire instead of the hot wire so the receptacle is always hot. So two mistakes cancelled out and I get a B+. To have a constant common wire, I just ran one back to the fuse box through the conduit in the foreground.

So today I added the last set of wires though this junction box to the bedroom and the basement is now fully up to code with arc-fault interrupters. As a final touch up I unscrewed the connector to the smoke detector hot wire to reposition it, forgetting it was a separate circuit on which I had not cut the power. When it touched the metal box, the light turned on. DOAH! No harm done but I had to drop my overall grade to C-.