Where to apply for benefits to get paid for providing and caring for an elderly person?

My father in law is currently living with his son and I. He is currently receiving social security and disability benefits. We heard that we can get paid for providing care for him, not only because he is living with us but because we also provide for him. We provide for him not only financially but emotionally as well. We take him to his Doctors/Dental visits as well as buying all his monthly supplies, like tooth paste, food and etc. I would like to know if any one can help by letting me know where do i apply for this type of help at?
Thanks In Advance!