On August 4, Gravis Polls released Wisconsin poll results. The only minor party or independent candidate included in any of the Wisconsin polls is the State Treasurer’s race. The results: Republican Randy Melchert 39%, Democrat Dave Leeper 31%, Green Party nominee Ron Hardy 12%, undecided or other 18%. See here.
There are also Libertarian and Constitution Party nominees for that office. The pollsters probably decided to include Hardy because he is a Winnebago County Supervisor. He was elected in 2012 and has already been re-elected in 2014. The office is non-partisan. Thanks to Michael for the link.