Wiper gremlins

I've had an issue with my wipers being possessed at times. It sometimes doesn't occur until 30-60 minutes or more into a trip. They will begin wiping intermittently, usually approximately every 10 seconds, but the frequency sometimes varies. There WAS a short found behind the dash by the mechanic when I bought the car, that was affecting the gauges, but this was fixed and gauges have been fine. I thought that perhaps the problem is in the steering column, probably the wiper stalk, but doesn't explain why it would happen so far into a trip, since most of the sharp turns would happen pulling out of the garage, onto the street, etc. anybody have any insight? The local Ferrari dealer said they couldn't fix it since they couldn't reproduce it.