2000 Chevy Impala Wiper Problem

2000 Chevy Impala 4 cyl 162000 miles

I have a problem with the wipers in my Chevy Impala 2000 model car. The problem is that the wipers do not turn off even when the wiper switch is turned off. I got the wiper motor and the wiper switch replaced and the fix worked for few days. But when it rained, the same problem started again and I ended up wasting $200 odd without the problem getting solved yet. I have observed that when it rains, there is some water flow sound coming from the front dashboard of the car. So I am thinking that the water messes up the wiper circuitry board and shorts it. So I believe a fix to the water problem is required first and then probably replace the wiper circuit board again. But I am not sure what is the exact problem. Any help would be highly appreciated.