Battery Drains while shut off
 

Re my 1999 Park Ave. I must start this car everyday and let it run, or battery will be drained and I have to do a recharge. After sitting two days battery is too weak to crank the starter.

To try and solve this I did the following: installed new battery, unplugged the trunk light bulb, glove box bulb and the under the hood bulb. I watched the car at night and no lights were visable (except the flashing security light). No sounds of anything running, like a fan. But something is using current while car is completely shut off. Anyone have ANY ideas?