Okay, all breakers appear to function correctly - Power when ON, no
power when OFF. So I looked at the switch, and it looks like all
there might be two circuits connected together right then and there.
The box actually has two switches, which are on different circuits,
but the hots, neutrals, and grounds are bound together. I
disconnected them, took the switch out that controls my lights of
interest, and put it back together as it was, just with one switch
missing. now the lights have no power, nor is there voltage between
the hot and neutral of the wire that goes from the last light to the
switch that was removed. I see nowhere else where power might be
coming in from, as all there is now is the 4 lights with wires
connecting them. I'm guessing therefore that power came from the
switch and I've successfully disconnected it. Do you guys think I
should continue my search for what was going on here, or just be happy
that I accomplished my mission. E.g., is it truly a danger or fire-
hazard to leave as-is? Hasn't been an issue for the 10 years the
house has been standing. Thanks again.