I guess you have two options, keep quiet about what you found to keep the peace, or confront him, if he is physically abusive, confronting him may not be such a good idea, stash the evidence for when you have someone around for support. If he is not abusive then maybe wait till he has been home and settled down and then bring out the cans, he will be upset at being caught out, but he should know that you know, you've kicked him out once, so he knows you can do it.
Whatever you decide to do, don't put yourself in danger, keep a level head, count to 100, or ignore him completely and go to bed.
Hope you sort it out, my thoughts are with you.