If he dies without a will you will get a portion of his estate through intestate succession. The house would pass to whoever the other co-owners on the deed are or to whoever is listed in the deed as "transfer on death". His wife would have the right to determine whether he is hooked to machines or not without a living will and/or healthcare power of attorney.
Parents should remember 3 things: Love your kids more than you hate your ex; when you have children the relationship with the other parent is until death; your children determine what type of nursing home you end up in.
Nothing stated by me should be taken as giving you legal advice or forming an attorney/client relationship.
Attorney-GAL in Ohio.
I've removed the knife from my back, polished it, and will one day return it -- long after you think I have forgotten.