What would you do?

Our friend suffered some sort of a mental breakdown and is experiencing severe psychosis. He's making strange connections with numbers and talking about aliens. His wife who is a nurse to him to the hospital and they admitted him into their inpatient mental health facility. His wife called me today to let me know he might show up at our house. Evidently he refused all medications claiming he is being poisoned. He also said that my husband and I are his only friends and he will go live with us. Then he walked out of the facility and is now walking the streets. His wife said he is a danger to himself and others. The doctors say the same. He can't live with us. He does need help. He has done so much for me and my husband. He believed in us.
What would you do?