Having a slight electrical issue...need guesses

Ok heres the deal… one day i go to leave for work car was fine 7 hours before. I turn on the headlights and hear a buzzing and my open trunk and door open light come on. Also when i turned the lights on the dash clock turned off. So i figure there has to be a relay bad or something so i pull the radio out to find this odd buzzing and its coming from a box behind the radio with interlock control written on it. So i find out that is for autos and my 91 is a 5 speed and also there is nothing plugged into it. How is it possible a little box with nothing plugged into it is buzzing when i turn the lights on. I was thinking that since its mounted to a metal bracket that something back there isnt properly grounded and is making all that stuff go haywire? Am i barking up the right tree here. And i found that when i pull out the Taillight/dash lights fuse all the craziness goes away and everything works fine. I would just keep that fuse pulled except for the lack of taillights… Any opinions are appreciated…sorry for the long post also.