While there’s no Wisconsin statute specifically addressing pedestrian right of way in a parking lot, §346.62(3) forbids causing bodily harm to another person by negligent operation of a motor vehicle.
Since pedestrians are common and expected in parking lots, a driver who hits a pedestrian in a parking lot can pretty easily be found at fault for negligent operation of their vehicle. Common examples include distracted driving (especially looking at a smartphone), speeding, or simply failing to yield right of way.