Based on their own document here:
125,000+ votes were cast for Supreme Court in Waukesha County. The next most voted for race had a total of about 106,800 votes. That leaves just over 18,000 votes for only the Supreme Court race.
18,000/125,000 = 14.4%
A Republican was complaining about fraud in Dane County on election night because there were some 10,000 ballots cast for only the Supreme Court race. However, there were a total of 182,000 votes cast in Dane County.
10,000/182,000 = 5.5%
There were about 172,000 ballots cast for Dane County Executive, confirming the 10,000 number.
If the Republican had his numbers right, that would mean that Waukesha County had three times the number of SC race only ballots. If you took the number down to 5%, there would have only been 6000 such votes in Waukesha County. That means a loss of approximately 12,000 votes, pretty close to the number of votes that were added for Brookfield today.
Update: If anyone has the time and ability, it would be great to see if this is an anomaly when compared to the rest of the state as well.
Late Update: Looking at some of the counties, it is pretty hard to compare some as they did not have another competitive countywide race, such as Milwaukee, Washington, and Jefferson Counties.
However, I will try to update with some that did have some competitive races:
5,500/60,500 = 9.1%
2,700/32,000 = 8.5%
1,500/43,500 = 3.4%
4,000/51,000 = 7.8%
800/30,900 = 2.6%
Winnebago (closest to Waukesha)
4,700/39,500 = 11.9%
No Competitive Race:
Crawford, Dodge, Eau Claire, Fond du Lac, Jackson, Jefferson, Kenosha, La Crosse, Manitowoc, Milwaukee, Ozaukee, Portage, Rock, Walworth, Washington
This includes all counties with at least 10,000 votes for either candidate.