My bet is that it is a defective switch. Why do I say that? Cause I'll be by the dealer tomorrow to pick one up. I've tried a number of things to free up the contact button but it just doesn't last, so new switch it will be.
It happened to me too. it is very disturbing to have found out that when you're braking with the front that no light is coming on. Always check your lights...remember T-CLOCK.
Any way, I was on the road when mine failed, the local dealer did not have one...so I got some WD-40 and sprayed it into the switch. If you look closely, under the switch there's a little hole in it. also, it no big deal to remove it for some bench work. road side rest stop that is. I'm carrying a spare from now on when I hit the road for an extended trip.