snip

Your GFCI thinking might be a red herring in this case. Does
"testing my breaker box switches for an outlet match" mean that
you went through and turned each breaker off and then on again to
determine which breaker was associated with which outlets? If so,
consider the following:

Thanks for your response. I'm also leaning away from the GFCI solution
at this point. Yes, the breaker test was to see which one went with each
of the outlets and switches.

snip

The problem may be with the main breaker that feeds those
outlets. Since asking if you actually turned all of the breakers
back on after your test might be a bit too obvious, I won't ask
:-)

Yep. In some cases several times to ensure a firm position.

snip

It's possible that the main breaker for those outlets had
either tripped or failed internally when you returned it to the
"on" position after testing it. If it is tripped, there will
likely be a colored flag on the breaker indicating this and/or
the lever on the breaker will not be all the way into the "on"
position. A breaker that is tripped cannot be put directly back
into the "on" position by just pushing the level in that
direction. You must first reset the breaker by turning it off.
Then you can put it back into the "on" position.

The leading contender for the breaker switch is labeled "GFCI garage"
and it is on a funky set of four switches, the middle two of which are
ganged and include the suspect switch. The outer two switches are ganged
as well. The switches, however, don't have the external characterstics of
being tripped because they switch quite readilty between an ON and OFF
state and stay firmly in the ON position.

snip

If none of the breakers appear to have tripped, then you need to
remove the panel on the box and go down the row of breakers with
a meter to see if any of them have dead outputs even though they
are turned on.

I certainly can do this if I need to. My understanding is that I need
to measure the voltage between the neutral bus bar (located near the top of
the box?) and the terminal (is there only one?) from each of the switch
locations.

Thanks again for your help.