Tracey,
My great-grandmother Bertha Mielke lived in Rib Lake (I have a photo of her there with her husband Herman Hanke - probably on or near Mielke Road. Herman was originally from around Dresden and the Mielke's likely were too) and would have been old enough to be your grandfather Clarence Mielke's aunt, since she was about 43 years older than him. I would bet 10 dollars she was either his aunt or grand aunt. Therefore, it's more likely your grandfather was born in Rib Lake rather than in Germany (he was born in 1910?). You will be able to get Clarence's parents' names via his death certificate in Madison.