I am trying to come up with a working dome lamp out of my collection

None of the candidates have continuity across the spade terminals. One of them has continuity from the switch terminals on each side of the switch but not through the rivets on out.

Any thoughts on how to repair the continuity?

Any thoughts on where to find a replacement switch. I have two that need switches

I might have something, I'll check later when its light out.

Hmmm, that's one switch that I've never taken apart... Now you have me curious.

I think I'll see if I have a spare and drill out the rivets.

IIRC, there may be something funky about the the cabin light's wiring and switching logic (even one of the terminals is 'different') that requires a special testing procedure. I'm thinking about how the lamp is controlled not just by its integral switch, but also by the door P/B's (wherein toggling the integral switch can override Door Open/Closed).

Bottom line: You may not have a problem at all (emphasis, however, on the word, 'may')

Perhaps we should ask CZCC's designated electrical expert (Steve ____? ) for some guidance before you add yet another cabin light to your collection.

Edited yesterday at 12:31 AM1 day by Namerow

I don't see anything unusual other than it has two possible grounds - one that can be provided by the dome switch and/or one that can be provided by the door switches. No one of them interferes with the operation of the other(s). All can be providing (or removing) ground in any combination of the three. The dome light switch itself looks fairly simple.

Edited 13 hours ago13 hr by cgsheen1

Weird - it's a turn-y switch - it rotates into or out of contact by pressing the button. That little black disc (brass contacts on the bottom side that I didn't take a pic of...) gets turned by the shaft above it. So, it needs to turn freely, have an undamaged top side (the little ramp, triangle thingy's), and the entire mechanism needs to slide / move freely, and all the contact brass needs to be clean. I didn't notice any old grease or lubricant in this one.

I was surprised that the "top" was just held on by a couple of clips on either side. Everything is PLASTIC and we don't have very good luck with PLASTIC here in the DESERT, so I was a little nervous. I heated the whole thing up a bit and used an extremely small screwdriver to pry one side at a time. First side was pretty easy - the second was quite a bit harder but eventually the "top" came off and revealed the underlying surprise. The switch is indeed simple and you can test continuity straight through on the rivets both sides or the brass the rivets tie down. Also check continuity through to the bulb holders to make sure corrosion hasn't killed the circuit between the switch and the bulb.

Edited 11 hours ago11 hr by cgsheen1

Here is how this one was wired: Main GND (B) is a male spade that pushes into a female held in that little box. Red/Black (RB) is the GND from the door switches. Red/Blue (RL) is +12V from the fuse box. And they're both female spades. You'll notice that the main GND can be interrupted by the switch and that the RB GND from the doors is independent of the dome switch.

Now. To refurbish this one AND try putting it back together - so that it still works...

Edited 11 hours ago11 hr by cgsheen1

Looks like I have mostly parts candidates in the hoard. None of then work smoothly.