We have a 5 yr old who's mildly autistic but can communicate needs and wants.
The sitter would pick him up from school or therapy and bring him to the house. Possibly feed him and or prepare him for bed if my wife is on call. She's on call 2 weeks a month. 6 to 10 of those days help is needed. The sitter will be needed 5 to 6 hrs. Outside of those 2 weeks the sitter will be needed on a as needed basis. You'll be notified with 2 weeks advance notice.