maybe the previous owner had a cool efan setup! probably lights tho lol

 

LMAO!!! Wake up McFly

 

Same darn thing on my truck.

Except it looks to be a red light but it doesn't turn on when I flip it.
So they were probably aux lights?

 

I have the same exact switch in the same exact location as the OP.
I believe mine was related to the trailer brake from the previous owner... Maybe?
Def. not factory wiring though

 

not factory... i had one like that, and was for a power lift for the bed that was removed... i found part of the control unit under the steering and removed (well, reused to bring power to the bed and have some auxiliary things there).

follow the wires... its easy to remove that part. a couple of bolts to remove the plastic cover, and if you need, you can also remove two other bolts and remove the metalic cover behind the plastic one to have full access.