Wis. Stat. § 946.47

(1) Whoever does either of the following may be penalized as provided in sub. (2m) : (a) With intent to prevent the apprehension of a felon, harbors or aids him or her; or (b) With intent to prevent the apprehension, prosecution or conviction of a felon, destroys, alters, hides, or disguises physical evidence or places false evidence.

(2) As used in this section "felon" means either of the following: (a) A person who commits an act within the jurisdiction of this state which constitutes a felony under the law of this state; or (b) A person who commits an act within the jurisdiction of another state which is punishable by imprisonment for one year or more in a state prison or penitentiary under the law of that state and would, if committed in this state, constitute a felony under the law of this state. (2m) Whoever violates sub. (1) is guilty of the following: (a) A Class G felony, if the offense committed by the felon being aided is, or would have been if the offense had been committed in this state, any of the following: 1. A Class A, B, C, or D felony. 2. An unclassified felony that is punishable by a sentence of life imprisonment. (b) A Class I felony, if the offense committed by the felon being aided is, or would have been if the offense had been committed in this state, any of the following: 1. A Class E, F, G, H, or I felony. 2. An unclassified felony that is not punishable by a sentence of life imprisonment.