I need a legal contract between two parties

My 75 year old brother wants to move from Texas to live with our 97 year old mother in a villa I own located in Leesburg, FL in a retirement community. His wife just died and he is not in good shape financially. I want a contract that spells out that for his assistance in caring for our mother he will be paid by free room and board. He will not have to pay for anything a long as he is helping our mother with all the duties required to make her life comfortable. Also, after her death he must leave the house in the same shape it was in when he moved in. He will have 60 days to locate and move to another living facility or house. Also, he has no authority to sub lease the house to anyone nor invite anyone to live in the house during his time that he is taking care of our mother.

If you can think of anything else to add please do.