it has to be a long-term character who knows most of the deceased. Ian, Dot, Sharon or maybe Phil would work.
It could be Nick but do people remember Eddie Royle or Ashley Cotton? They'd be the ghosts he'd see. The ghosts have to be known to Joe Public - Hev, Barry, Pat, Kathy, Arthur, Cindy, Den and Angie - people say that the more well-known characters won't do it but this is for CHARITY (Children in Need not her off Emmerdale!) so the 'bigger star's may have been more willing to return for a few hours to film.
This could be a lot of fun - East Street was the proper actors on the proper sets but it was more of a spoof - the two casts even sent up elements of their own shows!! Loved it.