01 F150 "ghost" door locks
 

I have an 01 F150 SuperCrew that has an issue with the electric locks. On occassion, they lock and unlock themselves sevreral times in a row, back and forth. This can occurr whether the ignition is on or off. Any ideas? My best guess is a ground wire in the switch wiring has rubbed through. But like I said, this has happened when the truck is at rest, without the ignition on.