Originally Posted by Wragie

This might be a bit late for some people who have done this but cleaning the contacts with edge of a screwdriver is actually a bad thing. That creates scratches and while it looks clean it will oxidize faster and the micro scratches will wear the surface faster until they or wha they touch are worn down. What you want to do is burnish the contacts. An eraser is what a lot of people recommend but that only removes some of the oxidization a proper burnishing tool will removes he layer and polish without causing the scratches that do more damage. A few years ago you could walk into radio shack and grab one. You can still order one from a electronics supply house but unless you have a lot of switches you plan to do the cheap way is to use plastic kitchen scrubbers held over that pencil eraser. The eraser provides a soft cushion and support. To use just twirl it until you see bright or clean metal. You can try spray oxide contact cleaner but again a can of that is a lifetime supply.

Until the pivots wear or the contact strips break from fatigue you can generally get any switch to work again. If the switch is no longer available you can still rebuild them with simple hand tools and a bit of time. The most complicated part of that would be something like heat treating a new brass strip.