I nearly electrocuted Patrick last Friday. He was putting in the chicken wire on the side by the bookshelves, and the layout lights were on. I had them plugged into a non-polarized extension cord. He touched the electric stapler to the chicken wire, and ZAPPPP. At first I thought it was just that polarity was flipped, but then I realized that the metal boxes weren't tied to the earth ground yet.
On Saturday I wired up a couple more lights and went to test them, popped the breaker. Took the two new boxes apart, and found that I had nicked the insulation on the black wire with the screw when I closed the box. That's when it hit me. I must have nicked a white wire the week before. Combine that with the flipped polarity, and Patrick touches the grounded stapler to the now hot wire, bingo!
So, today when Patrick came over, finding the source of the neutral bridge became the first order of business. We got very lucky, because once we determined that it was in the lower string of lights, we opened up the box in the middle of the string, and there it was. A little electrical tape and some careful reassembly, problem solved. Won't let that happen again.
Patrick sanded the putty on the backdrops, and I sprayed primer over the putty to seal it. Then we installed 16' of backdrop and decking for the Ford plant, while the primer dried.
The afternoon was winding down, and both batteries for the screw gun were dead, so we got out the blue paint and went to town.
Patrick will be back Friday. Pics after that.