Does the reverse lights work when in reverse?
Should be an easy fix. Had it happen to mine before too. There is a rod that attaches to a linkage by a cotter pin. This is located on the firewall where the steering column cames through. The rod follows the contour of the firewall and attaches to the transmission linkage on the front DS of the tranny. This rod will have a set bolt to lock it into place.
Fix: Loosen the set bolt so the rod can slide up and down. Turn the ignition on, don't start the car. Put the shifter in Reverse. Have someone stand behind the car. From underneath on the driver's side (car may need to be jacked up slightly) slide the rod up or down til the reverse lights come on. When they do, lock down the set bolt. Put the car in Park. If the lights go out, you are done. If they stay on, loosen the bolt and slide it up or down slighty til they go out in Park, lock it down again. Check that they work in Reverse and you are done. It is just a minor adjustment of trial and error but straight forward once you see what you are working with.
Hope it helps