On first glance of the footage, it seems to show an apparition walking across the hall. On further inspection, it appears as though the shadow is probably coming from the room at the end of the hall, to the left of the fireplace. Most likely just a reflection of someone walking around in that room.

Here is a full sized picture of the hallway shown in the video:

http://i.dailymail.co.uk/i/pix/2009/07/03/article-1197247...

If you look closely, you can see that the fireplace/wall is slanted, at an angle, explaining how someone's shadow could be cast without them actually walking in front of the fireplace. (less info)