I don't know that they need an "enforcer", at least not as typically thought of in the NHL. I really like their group of forwards and just throwing some bruiser out there seems like a waste to me, in today's NHL.
In my opinion the one real hole the Wild have now is a sizable guy back on the blue line. Power forwards are having no difficulty getting and maintaining position in front of the crease and the Wild have no one who can move them out, even effectively tie them up. Faulk has a little size, but isn't getting it done consistently.
I love their defensive guys, but mostly from an offense standpoint. If they were going to add anyone, I'd like to see a 230 lb. defenseman with at least some ability, and not afraid to mix it up. He might serve the "enforcer" need too, if necessary.