the wiper motor should park, IE...store below the hood. Most likely you have a park switch problem with the wiper motor. I have seen a bad ground on the motor also do this, make sure the ground strap for the wiper motor is in place and making good connection. You can take the wiper motor apart and try to clean the park switch contacts..or just get a rebuilt and detailed wiper motor. check all the connections at the wiper motor plate too.
Good luck!
:beer: