If you secure only one wire to each screw, I don't believe it's possible to
short anything out. There is nothing internal in the design of a three-way
switch which would cause a short. (Take a look at the schematic in komobu's
link.) Secure the wires to the new switch, but let it hang out of the box
where it isn't touching anything. Turn the breaker on. Then put gloves on
and check the new switch to make sure it's wired correctly. If it is, turn
the breaker off and install the switch in the box. Then turn the breaker
back on. If your system is grounded and the new switch is hitting something,
your breaker should trip.

however, that was in a different house. What I'd like to know is: Is
there a way to test the wiring BEFORE throwing the circuit breaker
power back on?

The need for a way to test it first is because the breaker box is
downstairs into the basement and then to the opposite corner of the
house. I worry that if the switches weren't wired right, I might see
pretty sparks when I run zoom upstairs and around a corner to check on
my repair job. And then have run zoom back downstairs and across to
make sure the power is back off. Just the thought makes me nervous.

Any hints or ideas will be gratefully appreciated.
Thank you,

"Wilma Harrington" wrote in message
...
Advice please - 3 way light switches - I just moved into an older house
where the light switches in the entry way seem to be terribly confused.
(There are 4 switches 2/2 - porch light, coat closet, on/off hall light
from upstairs, on/off same hall light from downstairs) I've replaced 3
way switches before so that's not the problem (famous last words?),
however, that was in a different house. What I'd like to know is: Is
there a way to test the wiring BEFORE throwing the circuit breaker
power back on?

The need for a way to test it first is because the breaker box is
downstairs into the basement and then to the opposite corner of the
house. I worry that if the switches weren't wired right, I might see
pretty sparks when I run zoom upstairs and around a corner to check on
my repair job. And then have run zoom back downstairs and across to
make sure the power is back off. Just the thought makes me nervous.

Any hints or ideas will be gratefully appreciated.
Thank you,

Wilma Harrington