My electrical panel is mounted on bare studs of an exterior wall in my attached garage (living space above). The garage is not insulated and it does not need to be (except for the ceiling which will happen someday soon). I would like to mount my electrical panel on 3/4" fire-treated plywood, and I was planning to keep the stud cavities empty. Location is moderate SF Bay Area.
Do I need to be concerned with adding a vapor barrier?