All the switches (except the master) have the same electrical connection.
All you'll need to do is swap the switch in question with one of the
others to see if it's the issue.

The switches pry out, but it's tricky.  I usually use a round-shaft pocket
screwdriver to get under the flange on the switch plate and press in the
clip under the door panel surface to release that end of the switch.

Unfortunately, it's difficult to describe exactly what's occurring, and
you probably won't understand until you have the switch out to see it.
Most of all, be careful.  Breaking the clip on the switch isn't a big
deal, but you can put a nasty indentation in the door panel if you're not
careful.