What does this knob do?

[hex7f7f7f]

The title should imply that this question is probably going to be stupid...

To the right of the ignition in my 66 c10 there's a knob exactly like the wiper knob. It's not connected to anything and there's so many loose wires under the dash (p.o. put in a lot of wire mess with the speaker/stereo/misc. accessories and then seems to have painted them all black...) I'm not sure which, if anything it should connect to.

Owners guide says it's a "Cigar Lighter (when used)", but I don't see how this knob would be that. Should this knob even be there? I'm tempted to just pull it out.