Speak to his doctor first. Find out if you’re dealing with alzheimers or what. If he hasn’t been to the doctor, take him. Doctor will have suggestions. Maybe home health, daycare, med revision depending on diagnosis. That’s my suggestion. God bless!
Most counties have a visiting nurse service which might be free, so if you first get him to a doctor for evaluation, then if medicine is required and some nurse attention is necessary the doctor should be able to advise you of how to reach them. It may be a simple problem. His will and other such is probably in a safe deposit box.