Battery draw/going dead over night

Hi, the battery goes dead over night if i pull the dome/brake light fuse there is no draw but every other fuse shows a draw of some sort. I'm trying to help a friend the car is a mess wiring wise. I don't know if someone tapped into a circuit causing this problem. It does have a fused wire for the amp fused to the battery (not my doing} I personalty think the fuse box/electrical system is being overloaded by all the accessories and should be upgraded. Any thoughts besides tracing every wire with a eyelet or aftermarket connector? It's one of those why did you mess with it if you didn't have a clue what you were doing. Any help is appreciated I did disconnect the alternator no change. It's has to be a big short sparks hard when trying to connect the battery. Am I overlooking something without taking apart and tracing each wire? Have a great day.Neil