Ghost in Radio

Had a browse through Radio associated problems but didn't notice this..My standard Radio/cd /tape player in my 03 D2 has now taken to coming on by itself....This can be anytime day or night, when the car is locked..I did have problems before trying to turn it off at the Radio and would have to power down the ignition in order to do so...but now it just comes on itself..Obviously will run down the battery so in the meantime I have removed fuse either 15 (I think) in interior fuse strip..We have had an awful amount of rain lately and whereas I have fixed so many leaks and cleared drains I know I didn't get them all....that's an endless cycle...Any ideas,probably looking at taking the unit out ,if you have done this before do you think its possible water could get in over the on/off contacts....but looking forward I think I'll break the positive wire to the radio over a switch if I can locate that..Thanks for any help..I can't drive far without audio...