Do you mean that the the door unlocks by itself while the car is parked or while you are driving? I have never heard of that happening. All doors or just the driver door? I would start by examining all the wires in that door, looking for damaged insulation.
There is nothing in your door that you can't fix yourself. The only special tool required is a Torx head screwdriver to remove the two screws that hold the inner door panel to the door structure. Be careful with the snaps coming off, and more careful going on, as both the snaps and their anchor points can break if you abuse them. You can see a door being taken apart on my web page.
Cabin_Filter (not sure why this URL ended up with that name)
The most common failure is the actuator. That can be removed and replaced fairly easily once you get the inner door panel off. Note that the actuator and the lock must be in the same 'mode' (locked or unlocked) so that the levers match up with the slots in the actuator when you snap the new one in place. On a '96, nearly all the electrics have been incorporated into that removable actuator, so there is rarely a need to take out the key lock or the latch mechanism.
If you have to remove the latch mechanism, that is a bit of a PITA and requires patience to remove and replace because there are several linkages that have to be manipulated simultaneously, but it is doable. I did one recently on one of my '97s because I did not realize that I could replace the actuator without removing the latch mechanism. It is not a job you want to tackle outdoors in the weather, and you need a good light to see what you are doing with those linkages.