I spent some time looking through data from the Wisconsin Blue Book. I looked at most of the major elections going back 20 years. Remember, Kathy Nickolaus has only been the County Clerk in Waukesha for about 10 years.
I collected the number of votes received by the two major candidates only, in republican-leaning Waukesha County vs neighboring democratic-leaning Milwaukee County. I've plotted the rise and fall of votes cast for these parties, along with the percent voting republican.
It's not conclusive, but I see nothing here that indicates foul play in Waukesha County. There's no obvious change in voting pattern vs Milw. County, before or after Ms. Nickolaus took office.