Brake Light Switch Keeps Failing

I drive a 2001 E320, and the brake light switch keeps failing. The first time I replaced it was about 18 months ago, it lasted 6 months and then the next one lasted 12. I'm about to replace it again, but I was wondering if there's anything else that could be wrong with my car to make them keeping failing?
I should note both were original parts purchased from the dealer.
Also, this time I do have a strange symptom. The first time it failed I just got the " BAS ABS and ESP" warning lights, the 2nd time I got all those warnings but my brake lights stayed on all the time, now this time I have not gotten any warnings, but my brake lights are staying on. I did check all the fuses and everything seems to be in its place.
Thanks for the help!




