What famous comedian turned down the role of Winston in Ghostbusters?

I guess I just assume every actor or actress cast in any movie ever was the perfect fit for that role from the get-go. But turns out a lot of classic movies could have been way different had those originally offered the roles actually taken them.

I can't imagine Ghostbusters with anyone but Ernie Hudson playing Winston, but apparently that very nearly didn't happen. Who was offered the role of Winston but decided to turn it down?

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