1973 450SLC Parking Lights Won't Turn Off

[Bowmen]

Out of the blue, a little smoke appeared from under the dash on the passenger side of my 1973 450slc. After turning off the engine, I noticed that the parking lights would not turn off. I had to disconnect the battery to get them to shut down. Checked the fuse box and all seemed ok. Does anyone know if there's a relay involved that may have gone bad? Jim K. Nashua NH, Mint 1973 450 SLC 45,000 orig miles!! Has this happened to anyone out there?? Thanks to anyone who can help