They don't say exactly where it was recorded, but it was captured during one of their investigations with a stationary infrared camera.
They say it is "to date the best piece of footage we have ever captured."
We do see movement in the doorway, especially in the enhanced version, but is this something anomalous or floating dust, etc. picked up by the infrared camera?
I think it's of sufficient interest to let you view and come to your own conclusions or offer your own suggestions.