- Yes, 4v went away with breaker in off position.
- Circuit is fed from subpanel, yes.
- It is an independent 15A breaker switch.
- I have not seen any boxes. The subpanel sends out a thick orange wire affixed to the ceiling (exposed beams) and then that line disappears up into the ceiling. I believe it's run along the length of the top of the house to feed the first outlets and then that is run down to the basement, where the other outlets and my audio gear is. All outlets show reverse polarity.