9900 cab lights

[the missing link]

So I have a 9900 2007-8 depending on which way you go .
The cab light ( 3 way switch ) will start acting up every once and a while , the lights will start coming on and off by them self . Really sucks at night . So I did what every decent redneck would do I pulled the fuse and forgot about it for awhile but winter coming and I would like to fix them , just don't know where to start. Even if the switch is on / off / door they still do it .
Is it a bad ground or door switch , wiring , ect .if any body has run in to this, help a brother out please .

Thank- you

[Waterloo]

Replace the 3 way switch, and then go from there, which it kind of sounds like. They do fail. If that is not the cause, get the 12 volt tester and voltmeter out and start pulling things apart to run the wires.

[the missing link]

Yeah I'll start pissing around with it , I just don't know if it will show up when I am looking for it .