I was working on an ES the other day and the switch was hung, in the master cylinder, in the low position. I took a handle of a screwdriver and tapped on the reservoir for the brake fluid and dislodged it. No more brake light! Could be worth a try.

 

Yes, trivial things like these (it might seem) are sometimes the root causes of the indicator lights....a tap here and there might do the trick. Just like working on a TV during the 60's.