What advice should I give my son's adult stepbrother that won't work or go to school?

My son has a adult step brother that was living with his other brother on and off for several years. He was homeless and the other brother took him in and helped him get a job. Once the adult step brother found another place to stay, he vanishes into thin air. No calls, no reason why he left, nothing. Unfortunately, every time things didn't work living somewhere else, the adult stepbrother pops back into the other brothers life and gives him a sob story and the other brother takes him back under his wing. Well, last week the other brother refused to let him back in after ANOTHER disappearing act he did 2 months ago.

Now the adult step brother trying to call me for help, but I refused to answer. I texted him and told him to get in contact with his dad ( My sons Father) and ask if him and his stepmom could help. I told him I can't have him living at my home. My son says he never calls him or talks to him. He never calls me either, until the other day for the first time. I also gave the adult step brother info to shelters that will help him transition to work and residence of his own. Am I being wrong for not letting him stay with me ?