where is neutral safety switch

Without the proper wiring diagram, Here's what I would do... remove the left kick panel, separate the rear harness connector identify the purple to rear lamps. Any small power source up to 12 volts would be needed. I have sat the cars battery in the front floor but that isn't recommended. Apply the power to the purple going forward and take a volt meter or test lamp to the bulkhead connector. You should find the power. That's where your purple goes.
At the fuse box, don't completely remove the fuse that supplies the reverse lamps, but separate it from the top so you can apply power to the exposed end of the fuse.
Now if you can find the power at the bulkhead connector, that's where the white goes.
Diagrams would be easier