Hi Mary! So sorry. You've been through alot.
I have a brother that is a paranoid schizophrenic and we have not seen or heard from him in years. When my Dad died, he had not yet been diagnosed. I thought he had a bit of a breakdown personally but realized very soon that this was more than just denial.
At first I tried rationalizing with him and soon realized, by the look in his eyes, that that was not going to happen. He deteriorated and mom took him to a pscyhiatrist. He was put in a "home" and did well on meds but soon, as others have indicated, didn't like the way they made him feel, refused the meds and walked out the door. I beleive he has made a few scary appearances but without the proper medical treatment, interventions and environment, he was off and on his own.
I expect he might show up on my doorstep one day. I don't know how I'll react and I guess it will depend on how lucid he is. That day I confronted him and recognized that "look" in his eyes, he had yelled at my daughter and scared the Bejesus out of her. I think she was about 8 and she thought he walked on water. We were nose to nose, eye to eye and I have to say, I was afraid. He was also drinking very heavily, every applicance, tv and stereo in the house was on. Eventually I was told that it was to drown out "the voices".
Although I know virtually nothing about the disease except what I've shared, it is my understanding that keeping a P.S. medicated is difficult because they cannot appreciate the benefit of taking the meds. Do some research. Make phone calls and someone mentioned a support group (great idea!). You and your son will need to be armed with all the information you can get whether he moves back into your home or lives somewhere else.
Blessings and prayers to you and your son. One day at a time, one moment at a time.