Engine Shut Off Question

[MAPerez05]

My engine will cut off and turn right back on. It happens a little often. I've noticed more often if I've just put it in reverse, it'll shut off. But turn right back on. Not only in this instance though. It also happened when I was driving, maybe about 35-40 MPH, it shut off, I put it in neutral, and it turned right back on.

What could cause this??

 

[94 Silverado]

The only thing that comes to mind for me is the switch on the transmission that only lets the truck crank it park or neutral. It might have some sort of malfunction to where it decides to cut it off randomly for a second.