Is my ex-wife entitled to any of my401K or pension

Under the statutes in the State of Wisconsin, all property acquired either before or during the marriage is presumptively marital property and subject to equal property division at the time of the divorce. The only property that is exempt, is property acquired either by gift or inheritance from a third party. Therefore, your retirement benefits are subject to equal property division. The court has discretion to deviate from equal property division based on the various factors listed under sec. 767.61 Stats. The 2 most common factors where the court may deviate is (1) the length of the marriage and (2) property brought into the marriage by either party. Your fact situation doesn't present sufficient information to more fully answer your question.