What if both switches are on? Is there a problem?


What you are describing will work, IF the two switches are
on the same circut.

A better way is if you follow the schematic at
www.goedjn.com/wires.gif (The top one),
using two-way switches. The safety ground is
omitted for clarity.

If the first switch is UP then power goes along the
line (a) to the center-pole of switch two, which is
pigtailed to the line leading to the lamps.

If it's DOWN then power goes along the other line to
the up-terminal of switch two, and if THAT is up,
then the lamps are on, anyway. Only if both switches
are down will the lamps be off.

The advantage of this is that: (A) it's fairly easy to
figure out whats going on, (B) it's hard to cross-connect
two circuts, and (C) the poor ******* who's coming along
after you can put the switches back into a normal X-OR
configuration by moving one end of wire 'a' at switch 'b'.