I have had problems with the whole ignition assembly on the steering wheel that caused crazy shit before so I think this could be a good possibility. Like currently if I hit my hazard lights or right blinker, my wipers turn on and run untill I turn the blinker off
:-/ 
HTH,
Zig
Hey Zig, that's a bad ground in the engine
compartment, try the little black wire on the
Pass Side, front by the washer bottle, it also
goes to the turn signal if you want to trace it.
This solved my wiper turn signal problem
Wild