Is the ignition tumbler lock supposed to pop out on a Cessna 172?

Never had that happen in mine, but the fuel primer has popped out a few times through the years. I have heard of the switches popping out on several aircraft. A friend's Beech A36 had that happen a few times. He got a replacement for it from Beech. Its just one of those irritating things that happen, but nothing to lose sleep over.