Shadow people are supposed to be "trans-dimensional", as in from some other world and cross over into ours.
And UFOs have sometimes been linked to crossing from other "dimensions". Though I've never heard Shadow People and UFOs being linked. But then I don't go in the UFO/Aliens sub-forum very much.
I've also seen several people who appear to be total cranks, who have claimed that bigfoot is trans-dimensional also and that he can disappear at will back to where he came from, and that no door or wall can hold him.
I've also read in a couple old books where bigfoot was linked with UFO activities. Such that immediately after a UFO report, several bigfoot reports would roll in.
My personnal belief is that most of what is reported as UFOs/Aliens, Bigfoot, Shadow People, Fairies and Angels are the same psychological phenomina, where a person sees something based on their own personal expectation. I'm not saying there is not a bigfoot, or aliens, but that a large number of reports could fall into a delusion catagory.
Say there is an electromagnetic event, like a thunderstorm and a large charge builds up on a hill. People nearby might think they see a UFO, and then others who scoff at UFOs and aliens, but are similarly affected would think they saw bigfoot, or a living shadow, or an angel. Thus one event of a natural nature could precipitate many reports of various phenomena. When everyone sees a UFO would be when it is on the news or otherwise communicated quickly, so that the mass delusion effect leads everyone to expect the same thing, or something similar to each other anyway. This would explain in part how several people can see the "same" UFO and the location and time are the same, but all the details are different.
Ahhh! Thank you DieChecker! What that tells me is that we should look at geological activity and weather events surrounding the event date and locale. Could well be elevated melatonin from Pineal gland activity in response to geological disturbances. Good lead. The earthquake/tectonic apparition phenomenon. I believe they also mentioned some strange animal behavior which would be consistent with electromagnetic field disturbance.