Wiper motor

[BLACKJACKф]

I have a 1968 square base single speed wiper motor I have done everything to try to figure this out when I start my car or turn the key on the wiper motor starts going by itself the only way I can stop it is to unhook the power to the motor. Any suggestions how I could remedy this problem like I said it's a square bottom not round parks on the right 1968 wiper motor single speed

[whistler]

Probably the switch is shorting out.