By law is there a minimum number of caregivers per resident in a RCAC and CBRF facility in the State of Wisconsin?

My mother resides in a RCAC facility as an assisted living resident. They have a chronic problem with being understaffed. The weekends are especially bad. I think it's a case of the RN isn't there so a caregiver isn't doing her job and tells me they don't have an RA (resident assistant ) that do the dressing. While the other caregiver is passing meds this one was sitting in the nurses office eating a bag of chips. A call has been placed to the RN in charge.