People who spend far too much time staring closely at the TV have identified an extremely small, blurry dark shape that appears to move rapidly across the stage during a semi-final performance on Britains Got Talent
. (Embedding is disabled on this video, so you've got to go to YouTube itself.)
It took me a while to even be able to see the "ghost." It starts at 0:51, at the right side of the stage. By 0:53 it's gone, darting off the left side of the stage. (Warning: it's really, really small!)
I think it's just a lighting artifact. Dave Tolomy, who gave me a heads up about it, thinks it may be something an audience member is holding up. Or maybe it really is a ghost! Decide for yourself, if you have nothing better to do.