There is power to one side of the coil then the other terminal is the ground path to the Electrolock switch. When the button is pushed in, the ground part of the circuit is open to ensure no ignition function. When button is popped out the circuit is complete to the breaker points in the distributor. The breaker points & condenser control the coil high tension induction but the circuit has to be hot to make it work. This is a good explanation.
https://modelagarage.com/service_bul...e-electrolock/
Folks sometimes forget to push the switch button in due to the car dying out or some other reason. If the ignition is left on and the points are closed, it can burn up the coil. If your lucky and the points are open then there will be no problem.