Garage Door Opener, Power to Motor Will Not Turn Off
Replace it, so you don't have to explain to somebody why you didn't replace it
I would replace this geezer of a GDO if I were in your shoes.  It did quite well to make it to 32, but outlived its welcome as it most likely lacks the auto-reverse safeties of newer openers (namely, stall-reverse/inherent protection and photoeyes/photosensors), rendering it hazardous to operate in the way one would treat a newer opener.
This would also be a good time to inspect the door itself for proper manual functionality and adjustment.