I have never had a switch turn off in the air due to air flow. I have had a switch destroy itself once because I did not properly mount it and vibrations took it out quite quickly. I use nothing but failsafe switches from Fromeco (Badger and Wolverine) now. If the fail for any reason, they fail in the on position.

If the switch is that lose that it is causing you concern, then it needs replaced. It's not worth risking a plane over