[DML] electrical problem

[birdstrike@xxxx]

The "key in the ignition w/ door open" buzzer stays on all the time,
just a little bit, barely audible. This continues when the car is shut
down and the key removed causing the battery to lose charge overnight. 
Is it a bad relay?? which one?? Please help I need to fix it up to
sell and don't want to pass on any problems.