If you jiggle the pedal or pull back on the pedal does it go off?  For some reason, alot of 68's have that issue.  I would replace it with a new one.  You could file the flat end of the booster shaft slightly, but if you go too far, it will come on later than needed.

That answer assumes a stock power brake pedal with a stock original style booster.  If you have CHANGED anything about the pedal or booster or master cylinder, let me know exactly what you have.

carnutjoe wrote:

Thanks Steve, I did try to jiggle the pedal and the light stays on. The car is a stock no power brake set up. I did order a new switch. I'll have it later today. I will be contacting you , hopefully sooner than later on upgrading to power brakes. Much needed with drums all around. As for the switch, does it use the tang that slips over the master cylinder to complete the circuit ?? Thanks again for your response.

Joe

 There are two different brake switches for the 67-68, one for pwr and one for manual brake. Both are a PITA so set up.
 If you are planing to change from one to the other it's an issue.
 you would be better off with a "T" in the brake line and using a hydraulic switch, which Ford should have done in the begining.

Thanks Steve, I replaced the switch and all is well again. I also found out, the switch that was in place was not a 1968. On the pressure switch as you say Rudi, it's probably the way to go. Since this switch is working now, next round I'll try the pressure switch. You know these oldies, there alway's a next round. Thanks a bunch guys,
Joe