I just did all of my dash switches, including the mirror switch, using the Radio Shack bulbs. The only difference between the mirror switch bulb base and the others is that it is made out of a rubbery material that slides down over two metal prongs. The bulb is 'threaded' in just the same way as the others though. (I think...) I guess if you pulled too hard on the little wires you might actually rip the holder but you'd really have to be tugging on it. On mine anyway the new bulb didn't even need a spacer to get the condom to fit back on as the new and old were the same length.