Our old '84 Pace Arrow had the same or similar Delco switch; as Eric says it's a common build for many if not most coach manufacturers. Ditto for headlight switches. Our PA had issues with both, and the parts were readily available at reasonable price from junk yard GM vehicles, especially if you removed it from one yourself, saving the junk yard guys the trouble. It's kinda like the standby "Ford" solenoid that's been around forever and used or copied universally; my first car '53 Customline used them as did our '52 Ford 8N tractor. Easy to get at and easy to replace! Your 12v electric bay solenoid is an example. Only relatively recently have electronic versions appeared that aren't subject to mechanical wear/carbonization.
Ignition (and headlamp) contact points easily overheat under the rare current or high resistance overload, and surrounding supportive plastic melts. If you're lucky there's no fire, just maybe smell and smoke, or perhaps nothing noticeable. But then, with the softened plastic, the contacts slip out of position and fail as a result. Your symptoms can be the result. New parts like Eric references can be a more expensive but best case option to junk yards.
Joel
