Hi all. I have a 95 Tracker with the 3 speed auto trans. Need to adjust/replace the back up light switch. Can anyone tell me where to find it? Is it on the tranny or on the shifter? Thanks for your help.

under the shifter cover

Looked there.  Unless it's built into the lock out switch,  didn't see it.

I can't remember, but it's under there, mine is slightly out of
adjustment and I have to bump the handle slightly to get it to work

It is actually built into the piece on the side of the tranny.  If you look on the passengers side of the tranny, you will see a black, kinda triangle shaped plastic piece with wires coming out of it.  You can loosen the bolt and slightly adjust it to make the backup lights come on when the tranny is shifted into reverse.  Note...this is also the adjustment for the Park and Neutral starting adjustment (so if you move it any, be sure to check that the engine will only start with the shifter in park or neutral and doesn't start in any other gear).