team are supported by some of the production crew, who appear in the show and are generally involved with the investigation whilst performing their normal crew role. Most of these on-screen crew members also take part in séances. From series 16, Antix Productions decided to remove psychic mediums from the format of the show. Some episodes have also included at least one celebrity. So far, the celebrity guests have included Vic Reeves, Nancy Sorrell, Gaby Roslin, Scott Mills, Mark Chapman, Simon Gregson, Sue Cleaver, Carol Thatcher, Paul O'Grady, and Lee Ryan. For the series 10 episode from Coalhouse Fort, the team were joined by Scottish paranormal investigator Ryan O'Neill, and series 15 saw Bullet for My Valentine join the team on an investigation. Former mediums Between series 1 and series 14, a medium accompanied the team on their investigations. The mediums were as follows: Derek Acorah (Series 1–6: 2001–2005) David Wells (Series 4–8 & 9: 2004–2007) Gordon Smith (Series 7, 8: 2005–2006) Brian Shepherd (Series 4, 5: Series 10–13: 2008) Chris Conway (Series 14, 15: 2009) The show has also featured guest mediums. So far, these have been Ian Lawman, Ian Shillito, Israeli-born Uri Geller, Rochford's clairvoyant Kevin Wade, American-born Johnnie Fiori, Barrie John, Liverpool native Billy Roberts, and American-born Patrick Mathews. It was decided for series 15 onwards that psychic mediums would not be used in the format. Former team members Series For main article on individual episodes, see: List of Most Haunted episodesThis section outlines changes across the 23 series of Most Haunted, with detailed look at major changes through the programme's original run (series 1-14), broadcast on Living and a brief series overviews and filming location lists if the revival series (15-23), broadcast on Really. Time slot Series 1: Tuesdays at 8:30pm on Living Series 2–13 Tuesdays at 9:00pm on Living Series 14: Wednesdays at 10.00pm on Living Series 16–17: Thursdays at 10:00pm on Really Series 18: Sundays at 10:00pm on Really Series 19: Thursdays at 10:00pm on Really Series 20–22: Fridays at 10:00pm on Really Series 23: Daily at 10:00pm on Really Series 24: Fridays at 9:00pm on Really Series 1–3 (2002–2003) Known as Most Haunted with Yvette Fielding and Derek Acorah (This title was used until series 6) The first series began on 25 May 2002. Each episode had a duration of 30 minutes. However, reruns of these episodes have been re-edited to the full