plycuda

I have a 03 3500, had my trailer hooked up the other night and round 3 am I noticed it's kinda bright outside and my right brake light on the trailer was on. I checked it tonight and I have power going to the conector and the only way to take power off is pull the fuse for the right trailer lights. Truck lights work fine. I did a search but everything I see is on the lights not coming on. thks Danny