I'm taking a wild guess that you are talking about the switch which runs the window wipers. You also got to take into account what other functions it serves. What you are looking for is the turn signal switch i believe. Here's a link. Hopefully this helps ya.
Dealership (or Stealership) is not that bad in relationship of OEM parts cost, small example like my last trip to MB dealer for my center three slot vent "new" for $74.00 but the same on Ebay was $65.00( it was old,used & after my best offer) plus shipping. Electrical parts ? I would go to new @ dealer.
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