My father lived with his caretaker and she put him in home care with hospice without talking to his kids first. Now what?

Did dad prepare a new POA? A doctor's order/evaluation is necessary for hospice to begin. That cannot be done, if dad is incompetent, without POA.

Brenda, we need much more information to form an answer.   What are your Dad's medical needs, and does he have any memory issues?   How long as Dad's caregiver been with him?   How long has he lived in her home?

It is nice that the Caregiver has Dad living in her house to take full-time care.   There has to be a back story here that the Caregiver took it upon herself to call in Hospice Care.