"Let 'Em In" is a song by Wings from which 1976 album, it's the fifth studio album by Wings, released on 25 March 1976 as a follow-up to their previous album "Venus and Mars"? 
Let 'Em In: " A demo of the song, featuring Denny Laine on lead vocal, was included as a bonus track on the Archive Collection reissue of "Wings at the Speed of Sound".
i don't know