I have a possessed Dodge Caravan

[sceetz]

We have replaced the turn signal/wiper switch in our 1997 Dodge Caravan 3 times in the last 3 years. The turn signals work for about 4-6 weeks and then work sporadically for a couple weeks, then quit altogether. We have been dealing with our local mechanic on this and he has no clue. We took it to an automotive electrician who charged us $150.00 to tell us that he can’t find a problem. Our wipers are working. They turn on when you start the van, then stop. When they are on delay, the speed changes all by itself. I am in need of a van exorcist! Please help!