The newer switches have a small LED soldered into them. They also have a resistor, so you can just hook-up 12v source that powers with lights.
Maybe branch off from the shift panel light (they're LED's so current shouldn't be an issue)
Here's a pic of the inside of the newer style switches (the yellow thing is the LED).
The back door sw's are the same setup with an LED for light:
All in all, the newer switches are VERY rebuildable and with a good cleaning (in the ultrasonic) and modern lubes, should last a LONG time.
Of course, they are not "sealed" by any sense of the word, so one soda accident will ruin their day. But they are also easily torn down and cleaned again too!
I have a few switches that have the "window" logo worn off so they're now just round white dots in the middle (that the light shines through), LMK if you want one to try out.