My father has always been difficult to talk to, to work with on anything. He always knows more than anyone else. It gets worse as he gets older. He even gets violent. He has minimal dementia. He would not stay in a home. He qualifies for hospice and my sister and I will be sharing responsibilities over his care simply because neither of us can handle him by ourselves. We're not even sure that he will leave his rural home to move to my sister's home for hospice care. He is becoming unable to care for himself primarily because of extreme pain from an accident that happened years ago. He will be on morphine for the rest of his life. He simply doesn't like nor trust people, including his family. What would you suggest and how would you suggest we carry it out. Neither of us can stand being around him for long. He becomes very abusive.
Eventually, my cousins had to gain Guardianship and force place him in a VA nursing home with a dementia unit, where by all accounts, he WA the life of the party.
Can you pursue guardianship? That gives you the right to force place him.
I guess the other option is to leave him be. What is the downside to that? Has he talked, ever, about end of life choices? Does he want to be left to his own devices until he's dead?
When someone becomes unable to remain safe by themselves, it's not up to them where they go anymore. They may have vocal opinions, but that doesn't mean they get what they want. There are safe facilities for elders who will wander. They are purpose built for that exact situation and it's called Memory Care.
Take him to a neurologist and have a cognitive evaluation done. Then he probably needs to be in a memory care unit, not alone at home or living with one of you. Crotchety parents tend to behave better for people in medical uniforms and for people who are not their children. They'll be fed, cleaned, given medication at the right time of day every day, have activities, and looked after around the clock. It might change & improve your relationship with him not to have to be the caretaker.
A lot of the paranoia is probably coming from his dementia, and there are meds for that. My mother is on just enough Risperdol that she no longer tries to fight the care takers who need to move her, bathe her, dress her, exercise her. She's convinced 90% of nurses & doctors are frauds. Everybody is trying to kill her. That people swing her around by her arms all night or they toss her around. (She's 200 pounds and 63 inches tall, so I doubt it.) Moving her into memory care was one of the best things that ever happened to her. She probably would have died in her house if I hadn't moved her fall of 2013 (which still feels like last year to me!)
Anyway. Given that quite major factor, and that your father has never found it easy to accept help from you or your sister, would it perhaps be a good idea for the two of you to work on your own expectations of how much you're going to be able to do for him? Concentrate instead on building relationships with his care team so that you can be involved at a safe distance. Your father may be sincere in his preference to stay in his own home; and while emotionally I can understand why your sister would want to assist with his hospice care I think she might be setting herself up for a fruitless ordeal. What qualifies him for hospice, do you mind my asking?