in Wisconsin can you sue your husbands girlfriend for alienation of affection?

Generally the answer is no, although there probably still may be a criminal statute on the books for charging someone with adultery. Rather than involving yourself with suing his girlfriend, if you get a divorce, you can make the argument that your husband committed marital waste or squandered the estate by spending all kinds of money on what may be lavish gifts or expensive trips with his girlfriend; unless there is a significant amount of money involved, the divorce court probably won't get too worked up about your allegations, as this is not an infrequent problem; however, if a serious amount of marital funds were used for such purposes, the court can deviate from equal property division, by awarding a larger percentage of the marital estate for your husband's misconduct.