I am not a Wisconsin attorney, so please don't consider this to be legal advice.
Under the rules of the Wisconsin Public Service Commission (PSC), it looks like your electric utility has the right to transfer the account balance from your rental property to your home account, as long as certain procedures are followed. PSC rule 113.0301(7) states:
(a) Account arrears incurred by an owner or property manager for rental residential dwelling units ... may be transferred, without regard to class of service, to the home or office account of the owner or property manager.
(b) The utility shall send written notice of the planned transfer of the account arrears ... to the owner or property manager prior to making the transfer.
(c) If the account arrears remain unpaid ..., the utility may disconnect the owner's or property manager's residence or office service, provided that the utility complies with the disconnection provisions of ss. PSC 113.0301 and 113.0304.
(d) An owner or property manager whose account is subject to disconnection action may avoid disconnection of service by making payment, by making an agreement with the utility for an extension of time for a specific period, [or] by entering into a deferred payment agreement under s. PSC 113.0404 ... . Any disconnection shall be in compliance with ss. PSC 113.0301 and 113.0304.
So, if the utility gave you notice that it was going to transfer the account balance to your home account, then they acted properly. To avoid disconnection, you either need to pay the amount owed or you need to enter into a payment agreement with the utility to pay the amount over a period of time you and the utility agree to.
If you don't think the utility is acting reasonably, you should contact the PSC's consumer complaints group: