so far so good
I had a buddy of mine with a 98. 5 that had his switch shortout and melt. Going down the road at night smoke in the cab and everything. I have a 99 like you and have not had that problem. A few months ago my switch would flicker on and off, pulled it out and took it apart and found build-up on the contacts. Cleaned and reinstalled, haven't had a problem since. It does feel rather hot when running at night for long periods but no smoke yet.
Todd