Many pubs claim ghosts, certainly in the UK. We like pubs so it's not surprising that so many choose to spend eternity in one. Many Brits spend most of their lives in one anyway. Well, until smoking was banned in pubs, and now they are dying at an alarming rate because most of their clientele were smokers - but that's a different story.
There was a video on this story but it's been removed due to a copyright claim. The story might vanish as a result because it's nothing without the video.
The video is available in the local paper's website or by clicking on the 'video' link here. I'm not sure if this will work outside the UK because it's not a national newspaper.
Much as I would love to believe this is a ghost, and even though it looks to be the right size and fits with the seating arrangements in the pub and looks very convincing, unfortunately I can't escape the feeling that it's a small fly on the lens. I see it flexing its wings and then scurrying out of shot. I am not convinced.