Umm, replace the switch?
Seriously, if the switch is loose, pull the whole unit loose and look / listen for the leak.
But just going by what you say, if the switch is loose it could be the source of your leak.
97 Sahara, 74 Renegade, 72 CJ5, 55 Willy's (the Beast) Boss 302, 6:34 gearing, Bose 901 speakers.
God I miss that Jeep. Forgot the kinda Jeep, 80 SX4.