It’s always important to practice good customer service. Work with your employees ahead of time to train them on listening carefully to customers’ concerns, and on de-escalation and conflict resolution techniques. Approach the customer and ask them to put on a mask (a face covering will do, see above) while inside your business. Tell the customer it’s a State requirement. If you have the ability to provide masks, then offer a mask. This mask can be free or for purchase.
It’s helpful to put up signs telling customers that wearing a mask is now required in Wisconsin. Updating your web presence would also be helpful.