You tell me?

Ok heres the deal, I was sitting in my car the other day, and I noticed this screw up. When I hit my brake pedal, my parking lights turn on, my dash lights dim like they do when you turn on the parking lights and when hte car is off and everything else is off, if you hit the brake pedal with the door open, it starts beeping like you left the lights on. Got to be some electrical problem, any suggestions.