Odd Breaker Situation...
Changing out the cheapy light fixtures that came with the house, I turn the switch off, remove the old fixture, accidentally bump common (white) against frame (green) and breaker popped.
Measure white with DMM... AC-level is a few hundred mV (noise?).
Measure black with DMM... AC-level is even smaller.
Likewise black to white.
Touch black to green... nothing.
Touch white to green... pop.
Do these new breakers have the equivalent of GFCI built-in? ...Jim Thompson