Wipers burnt

[Zonaman]

Ok need some help with this one!

I had recently installed the intermittent wiper module (Revolution Electronics) in my 69 half ton. Worked fine. Today, driving down the freeway, the wipers start wiping. Switch in off position. Couldn't get it to shut off! It was switch in off position but wiping on regular,slow speed and I couldn't get it to go intermittent or any other settings. I pulled off, turned engine off. Ignition on again. Went back to wiping. So I stopped the engine and pulled the fuse. That stopped it. Back on the road and I smelled something electric burning. A puff of smoke from center in the general area of the wiper switch and motor area. Pulled over looking under the dash with a flashlight. Couldn't see anything obvious on wiper switch, intermittent module or wipe motor, like burned wire or scotch mark. At least as well as I could see. Pretty sure it was the wipers. Any ideas on what might have happened and where to start on this one? Thanks