I have a 1994 softtail custom and the rear brake lights stays on. I can't get it to shut off, ann suggestions?

 

Check your front brake switch, located in the r/h switch housing on the handle bar. If you've had your lever off or the switch housing apart the switch may not be seated in the housing with it's little folded spring holding it in place.

 

It's almost certainly your brakelight switch. I've gone through many of them after changing bars, controls, etc...

 

Let go of the brake.

 

There are 2 switches, one in the right handlebar switch housing and one in the rear brake hydraulic line. If the brake light goes off when you shut off the main ignition switch, chances are good that one of these switches is at fault.
There is an off chance that the tail light filiment in the bulb broke loose and welded itself to the stop filiment. Since bulbs are cheaper than switches, I'd try this first.