Wis. Stat. § 214.30: Membership.

(1)

(a) A holder of a deposit account issued by a mutual savings bank shall be a member of the mutual savings bank. Joint ownership of an account constitutes one membership.

(b) A member has the right to share in the net profit of a mutual savings bank, after payment of creditors, if the savings bank liquidates. This right does not permit a member to claim a share of net profits absent a liquidation and does not permit a member to seek liquidation except in any manner permitted by the mutual savings bank’s articles of incorporation or bylaws.

(2) An owner of stock in a stock savings bank shall be an owner of the stock savings bank. Joint ownership of stock constitutes one ownership.