Hi guys. I'm trying to help a neighbor with an unusual problem with his brake light. During daytime with the headlights off his brake lights work fine.But at night when he turns the head light on his stop light is on all the time. We checked the fuse/replaced both bulbs and tested the brake light switch all turned out ok. We both run out of idea what the problem is. I would appreciate if someone can tell me any possible solution. Thanks.