weird wiper switch on my 67 cuda.

Again my memory aint great... Should be 3 resistor wires on the outside of a 90 degree gear motor. ( You may find their insulation broken. Doesn't matter so long as they stay separate and dry. I was told that insulation contains asbestos. Don't know if that is true. They do get very hot.)
From off position the switch slides through a variable low speed until it end of range/travel which is the fixed medium speed. Then there is a detent click to high speed. Thus described as variable 3 speed.