I would go to his place of work with two friends and confront him oturight in public...

Stay away from my wife you sleazy creep, etc...

It's a brute force method, but if he knows you know where he is and you have two "yes men" behind you he will likely cower away... men who prey on vulnerable marriages in secret are COWARDS...

Humiliate him at work, that should wake him up and scare him off...

Make sure he knows you have his home address too...

he will TRY to pretend he has no idea what you're talking about in front of otehrs, or he will try to steer you into an office to talk in private... REFUSE.. just keep telling him to back off of your wife.. make a HUGE SCENE