Licensure follows the patient
The location that matters for telehealth is generally the patient’s, not yours. Sitting in one state and caring for a patient in Wisconsin generally means you need authority to practice in Wisconsin — via compact privilege or a Wisconsin license. See telehealth: patient in another state.
The law that governs this in Wisconsin
Caring for a patient located in Wisconsin is practice in Wisconsin, so it is Wisconsin’s own nurse practice act that defines what you may do and the Wisconsin Board of Nursing that applies it. That act is Wis. Stat. ch. 441 (Board of Nursing); Wis. Admin. Code ch. N 2 (Licensure).
The compact itself is separate law. Wisconsin adopted it at Wis. Stat. § 441.51 (Nurse Licensure Compact), which is what allows a multistate license issued elsewhere to reach Wisconsin at all — the practice act still decides what you may do once it does.
Compact status is not the only consideration
Even where a multistate license reaches Wisconsin, your employer and the Wisconsin Board of Nursing may impose additional requirements, and some roles carry their own rules. Compact status answers one question — it is not a blanket authorization to practice remotely.
APRN telehealth is separate
The compact covers RN and LPN/LVN licenses only. If you work as an APRN, your advanced-practice authority is granted state by state and is not carried by a multistate RN license — a point that catches out a lot of remote NP roles.
Since when has a compact license worked in Wisconsin?
Nurses holding another state’s multistate license have been able to practice in Wisconsin since January 19, 2018. It has been a member long enough that most guidance you find will be accurate on this point.