What does this switch activate?

Wild guess but here goes. In drag racing at night you have to have at least one light on the rear of the car. I did this by wiring the back up lights to ignition feed so I never had to remember to turn lights on. I know you said the previous owners didn't race the car, but maybe the others did. My point is maybe micro switch used to turn on lights when gas pedal is mashed to floor. Violet color wire went to back up lights. Or maybe used as a idol up solenoid switch when staging the car. Turned on when you did burn out. Turned off when you launched. Finally, maybe the switch needed to be hidden. Just some guesses?