Tail light keeps blowing out in the rain

[Jay Beezy]

Has anybody had a problem with one of their tail light bulbs blowing out in the rain? For some reason, one of my tail lights always seems to blow out when it rains.
I'm in Georgia and the remnants of Hurricane Jeanne is in my area and sure enough, one of my tail lights blew out when I was on my way home. For some reason, it's always the ones that flash when you turn on your turn signal. One time it might be on the driver's side. The next time, it might be on the passenger's side.
The last time they went out, it was on the driver's side. This time, it's on the passenger side. Is there something that I'm missing on my car that is causing my lights to go out like this in a good rain? I'm tired of having to install bulbs when I have to drive my car in the rain because rain manages to get into the housing where the lights are make them blow out.
Any suggestions as to what I can do to stop this?

[cadgear]

Never heard of this..maybe try to get some basic silicone caulk and try to seal the outside edges of the housing where the halves meet? I was going to say wiring at the turn signal switch but if its the high mount as well that may not be the cause. Plus I've never heard of the switch causing a bulb blow, but I suppose it could happen to someone somewhere.