"There were five of us taking care of him and we were all completely exhausted," Campbell's fourth wife, Kim Woolen, told People magazine.
"No one was getting any sleep and we were just struggling every second to keep him safe - we felt like it wasn't safe anymore."
Campbell has been living full-time in the care facility since the end of March. According to his wife, he spends his days playing games, gardening and participating in the scheduled programs.
"He's made friends there. Everybody loves him there. It's a beautiful setting, it's very secure," Woolen told People.
The 77-year-old "Rhinestone Cowboy" singer may have forgotten a lot of things, but not his love for music.
"He's got this little guitar … he picked it up and stood up in the living area in front of some of the residents and he played a couple songs," Woolen said, recalling his first day there. "Then he thanked them all for coming. Then he went over and laid down on the sofa and took a nap. It was so sweet."
Woolen told ABC News' "Nightline" in 2012 that that music is a "natural memory aid" for her husband.
"We're finding out, we think it really does help his memory and help keep him from declining," Woolen told "Nightline."
The country star and his family are documenting their struggle with the disease in a new documentary, "Glen Campbell … I'll Be Me."