I've had to change a bunch of em. Common problem on GWs, that and cruise along with the CB control switches on GWs...especially older bikes and/or those stored outside.
If you ever pull one of those apart, there isn't much to them. A small metal slider and spring. Once the original lubricant wears off/dries out, it's only a matter of time.
Last fog light ones I bought were off the internet....several sources, eBay, etc.
FWIW, one of the things I do is I never turn them (or the cruise control switch), off unless I have to.
I also use Radio Shack's Control/Contact Cleaner & Lubricant, Catalog #: 6400148. This stuff can be hard find locally sometimes. I just order it from em online.
I use the spray nozzle and work in behind & spray it on the CB switches....seems to work on those pretty good.
IF the fog light or cruise control switches aren't totally burned out, I've had varying degrees of success/failure in trying to get some of that spray inside those but it's more difficult as they're sealed pretty good.
On my own bikes, I spray those about twice/year whether they need it or not, especially the CB switches on the GW. Sometimes the volume control and/or radio channel control will freeze up too. That spray works good on those too.