Is there anyway that your husband could give him a job or take him to work with him? The reason that I ask is that because of his history of mental illness. It is sometimes hard for them to find work and become productive members of society. If he is employed that means that he can get on medication for his condition.
Either way, it should be your husband that talks to him. I am afraid that if you say something he may become hostile. Please keep an eye on your little ones while he is around. I will be praying for your family.