Light switch end knob internal pics?

I'd like to address a long time little problem on my car, but it appears somewhat troublesome to pinpoint the exact cause: I blieve it must be in the knob of the light switch.

My question is two-fold:

Does the knob pull off the stalk, and do I use a plastic bag to prevent little balls and springs flying all over the garage?

Does anyone have a pic of the internals?

Many thanks,

Jack.

 

Thanks!

I'll start there this afternoon and work my way through the system.