This is what we found on Wikipedia regarding the Ben Ufo:

The interdimensional hypothesis is a proposal that unidentified flying object (UFO) sightings are the result of experiencing other "dimensions" that coexist separately alongside our own in contrast with either the extraterrestrial hypothesis that suggests UFO sightings are caused by visitations from outside the Earth or the psychosocial hypothesis that argues UFO sightings are best explained as psychological or social phenomenon.

The hypothesis has been advanced by ufologists such as Meade Layne, John Keel, J. Allen Hynek, and Jacques Vallée. Proponents of the interdimensional hypothesis argue that UFOs are a modern manifestation of a phenomenon that has occurred throughout recorded human history, which in prior ages were ascribed to mythological or supernatural creatures.

Jeffrey J. Kripal, Chair in Philosophy and Religious Thought at Rice University, writes: "this interdimensional reading, long a staple of Spiritualism through the famous 'fourth dimension', would have a very long life within ufology and is still very much with us today".