@Helen427 As it's obvious from your posts on the forum, you are a very kind-hearted and compassionate person. Is this guest someone you feel you could talk to frankly? If so, I'd suggest making a time to talk to him at a time of day when he is actually sober, like after he wakes up in the morning (afternoon?) and has had a shower and breakfast, pointing out that he represented his intentions to you as looking for work, but that it's pretty impossible to find work if you spend your days drinking and never leave the house. I'm sure you'd be able to let him know that you understand he's in a difficult time right now, what with his separation and joblessness, and you are empathetic, but that you accepted him as a guest on the basis that he would be job hunting, and if he prefers to just drink all day instead, that it would be best if he found aother place to stay.
If he seems like someone who'd get belligerant and you don't feel comfortable talking to him like this, I'd just keep it real professional- he misrepresented his intentions, you aren't interested in providing housing to someone who just wants to sit around and drink all day, he's making you uncomfortable in your own home, and he'll need to find alternative housing ASAP: