Proof? You want proof? You can't handle the proof.
The show uses INFJs very, very sparingly. They bring too much calm and resolution to House (which is not what on-going episodic TV needs). That I can think of there have been only two fairly obviously INFJs on the show. The pregnant woman in Season 3, episode 12, One Room, One Day, and, interestingly enough, Moriarty (Elias Koteas) in Season 2, episode 24, No Reason.
Which is why Wilson (ISFJ) can't be INFJ, nor can Cameron (ENFJ).
And Wilson can't be ENFP either. Not unless ENFPs are all secretly ISFJs.
If House ever does find a proper INFJ, he'll have to dump Wilson.