Are you sure the headlight switch isn't turned all the way so the dome light stays on?
'59 T-Bird..[color:blue]'70 Mustang Convert</font color=blue>...[color:green]'72 Mach One</font color=green>
http://clubs.hemmings.com/baymustang/t-bird.jpg The Black BirdAt 42,she's the oldest in my Ford stable
Sounds as if the little switch in the door jam has a broke or missing spring inside causing it to stay grounded. Try pulling and pushing the wire that goes into it to see if you can get the lights to go out. If so that's probably the problem. It's hard to get to so you might not be able to do this without removing the switch. Good Luck!