Single wiper stuck on on 1996 Mercedes-Benz C280

The wiper won't shut off even though the wand has the setting to zero. Same wand has Highbeam and directionals.
One repair estimate was $1000.

Asked by for the 1996 Mercedes-Benz C280
Ouch! Welcome to Mercedes Benz ownership!
The electrical system on these vehicles can be quite complex, so it takes someone with good electrical diagnostic troubleshooting skills to look into this. It may be something fairly straight forward like a bad wiper motor, but if it involves digging into the control circuit, then you should find an experienced MB technician.