if u have a volt meter u can do a parasitic draw test. make sure all power is off, meanings doors shut and underhood bulb removed, remove negative battery terminal, connect voltmeter in series between cable and battery, have meter set to 10Amp setting. after doing that let the car sit for a few minutes and check the meter for any amperage draw. if there is draw( over .030Amps) start pulling fuses from under the dash one at a time until the draw disappears. this will atleast get u started as to where u need to look!
since the fuses are inside the car u will probably have to disable the interior lights some how, like remove that particular fuse before setting up draw test or maybe taping down the interior lights switch that the door contacts to the left of the dash. u dont want to blow any fuses in the multimeter!hope this helps!