I do not have a photo(deleted on accident), but here is a discription of what I came accross and I could use some help on figureing it out.
Home built in 1976 that had been rewired with new panels. There were a group of switches in the hall that did not work any more due to rewireing and remodeling. As i switched on the switch on the wall I heard a loud pop in the attic above me. I found a square D box with a blank panel cover and no breakers. It had several Romex wires in it. I took the cover off and found a horizontal bar with all the wires attached. Below the bar was a breaker looking item that would slide up and down as the hall way switch was turned on and off. Sounded just like a breaker popping. It had one white and one black wire attached. It almost looked like a contactor, but as it switched on and off, I never lost power any where.
HAs anyone ever come across anything like this?