In one particular saber I have a 12mm illuminated switch as the main. It worked fine for years, then one day it started to flicker when it should have been on solid. Eventually it stopped lighting up at all. I took the saber apart and the wiring still looked good. After some experimenting, I tested with my multi-meter and discovered that the LED would turn on if I reversed the polarity. If I put negative to the "+" pin and positive to the "-" pin, suddenly it started working again. This is the opposite of how it was installed so many years prior. So, I swapped the wires and put it back together. It's working fine now, but that's very strange to me. Has this ever happened to anyone? The switch contacts still work perfectly and never showed any problems.