Electrical Draw maybe
 

Ok.. Here is my current issue.. Just replaced Alternator, new battery, but the damn thing wont stay charged.. alternator is hooked up right, everything is gravy while driving, stays around 15 volts.. car runs great... if you let it sit past a couple hours, the car is dead when you get back in and try and start it..
Here is what i know for sure:
Not the alternator.. had 2 DIFFERENT oreilly's check it
Not the Battery.. If you disconnect the battery after you turn off the car, even if you wait 24 hours, when you connect it again, the car starts right up
but if u leave it connected it dies..
No interior lights stay on
Doors and Hatch are closed all the way
I was having this problem before i changed my alternator, but obviously wanted to wait until i replaced it before i posted to see if it fixed the problem
I think that covers everything
any ideas?

yeah i have been dealing with the brake switch issue.. but both rear lights are unplugged

I would guess something isn't turning off. One thing i would try is checking your fuse panel with a test light or multimeter for voltage after car is off and see if anything is still drawing a charge.

Door pins, hatch switch, hood light, map light, stuck electrical sensor.... Has the radio been rewired? Cigarette lighter on?

Like GypZ said, you've just gotta start checking all electrical components.