It was commented on, hinted almost but never further discussed. The mysterious person that suddenly appeared in the bottom right glass pane behind Anton and then in the next shot a split second later they had disappeared. Simon then commented on the "ghost" which you can clearly see and that was it.

Simon commented before the house was meant to be haunted and then he said he bought it. It was almost like a gimmick gone wrong.

In reality the real ghosts were the backing singers. Josh Daniels singing in front of Grimmy. Watch right at the end as he finishes singing the backing singers are there. In the next frame he then stops singing and Grimmy comments suddenly they have disappeared as he walks out the door. Then cut back to Grimmy and Ronson and the backing singers are back again. I rewound it a couple of times and they definitely are there one minute, then disappear, then come back again.

Whats going on ??? Its almost as though he sung it without the backing singers then for some reason they added the backing singers and he sung it a second time. Then in the editing someone made a cock up.

I thought it was Louis!

The josh Daniels no singers thing was only cause they sing 2 songs to their mentor but agree with the rest

Clearly someone just walked into shot and they were just joking around about it being a ghost.

It was Louis! Meant to be funny, but obviously failed