The men and women, between the ages of 45 and 85 -- described by police as "prisoners more than patients" -- were discovered in the attic Sunday evening during an inspection, ANSA reported.
Police said the patients were in a room that was dangerously cold and there was little space between them.
About 20 other patients at the nursing home were in "precarious" conditions elsewhere in the building, police said.
Patients paid almost $1,000 a month to receive treatment at the nursing home.
The residents were being transferred to other facilities.