Good question. I don't have the Ford EVTM for our cars, but you can try to bypass the safety switch. If you do so and you don't experience any issues, then you've isolated the problem. If it still persists, then look towards your ignition switch. I assume you're already attempted to diagnose other parts involving starting the car.
This video demonstrates how to bypass the safety switch with a 10-amp fuse.
This video demonstrates how to bypass the safety switch with a 10-amp fuse.