In another, SEPERATE but seemingly related, problem: I have 3+bare coming into a switch box to feed 2 seperate circuits (black-circuit [A], red-circuit [B]). When [A] breaker is off I continue to pickup ~7 volts on [A]! When [B] is turned off: [A]'s voltage drops to 3 both in the box and at the breaker. Assuming the breaker is faulty (leaking 3 volts) why would [A] pickup 4 volts from [B] when [B] is on? I have not tested the voltage on the reverse: [A] on [B] off. (Note: These 2 lines are connected to the same phase).
(I've confirmed these findings by using 2 testers).