96 Taurus randomly revs up and shuts off while driving

I have a 96 Taurus. Recently I have been having problems with it. After driving for a few minutes, my car will all of a sudden rev up a lot without me pushing down on the accelerator, and then it will either shut off or it will go back to normal and then do the same thing again. Please help. I don't want to drive the car until I get this problem fixed. Thanks!