This shadow ghost video is pretty much what it sounds like:
"I'll swallow your soul!" - Army of Darkness
during a paranormal investigation, a shadow passes in front of the camera.
At first glance, this is not at all evident and you must continuing watching for sometime to actually detect what "pastinvestigators," the authors of the film, are trying to point out. After several decreases in speed, the issue finally becomes evident.
A murkiness drops over or passes by the camera, which at first appears to be just a person walking quickly in front of the camera. However, when the film speed is slowed, it becomes apparent that it is actually a shadow without substance rather than a human person. Through the murky darkness you can see the features of the room, making the figure transparent.
According to Wikipedia, shadow people are often regarded as malicious or evil spirits. Wikipedia also says that shadow people can be explained as psychological phenomena caused by illness or drugs. However, I am not currently ill or on drugs and I see the shadow on that clip.
Of course, shadows are caused by an obstruction passing in front of a light source, so that could be all this is. But the narrative on the clip is somewhat convincing in that it points out that the shadow passes over the camera rather being reflected on the wall.
The group states that they determined the ghost is that of the building owner's father. Feel free to click through and comment on Pastinvestigator's video. However, be sure to be polite and constructive, please!