Garage Wall switch ?

[David Nasser]

2007 southern cal. house. Could not figure out what this
switch operated in the garage. Anybody have info on what
these type of switches operate?

[Michael R. Boyett]

Assuming you are referring to the device on the left then that appears to be a GFCI that controls the garage outlets. Did you test for GFCI protection at the garage outlets? Much like the one you asked about here.

[David P. Valley]

Yup, it'll reset a GFCI protected appliance or outlet.

Trip it, and you'll find it's source while inspecting.

[David Nasser]

There was a normal GFCI in the garage that controlled all the garage outlets.
This is what puzzles me...