Starter Engages while running in park??

I just bought a 2001 S10 LS regular cab short box with a automatic and 2.2 engine. It started fine and ran great, until after I got home (around 30 minutes later) and shut it off then restarted it, the starter at different times kept trying to reengage while running in park. "Seemed to quit" when put into neutral or drive. Tried to move and tap on the ignition switch and key, but didn't seem to make a difference. Shut it off one time while doing it, and when the key was returned to just the "on" position the starter started engaging and truck started and it stayed engaged again. But haven't been able to duplicate it since, but I haven't taken it anywhere, due to the problem, maybe it would only do it after driving for 30 minutes and getting warm?? It's not on the road yet, borrowed a dealer plate to drive home. Any thoughts would be greatly appreciated. :runaround:

Sounds like a bad ignition switch, allowing electricity to engage the starter. The only other thing is a wire shorted to a hot lead.