Like the title says. The break lights on my brothers 02 explorer stay on and wont shut off. He has to disconnect the battery so it wont drain. Could it be a fuse or something like that.

Take a look at the brake switch. Sometimes you can pull up on the pedal and they will go off. sometimes the switch gets a little out of position and sometimes they just fail and stick on. All the fuse does is supply the power to the switch. If the fuse was blown than there would be no brake lights.