Hi,
I'm in Wisconsin as well. That's either a European Garden Spider, or a Barn Spider. Check & see if it has a white cross pattern on the top side of it's abdomen.. if it does then it's a European Garden Spider.. also known by some as the Cross Spider. The females can get huge, w/ body sizes reaching 3/4" or more. They are from the Araeneus orb weaving family, & are considered harmless to humans.