While it is true that man has developed instruments to measure fields undetectable to the senses, we should remember that before these instruments were built, the NEED for such instuments was suggested by observable, repeatable EFFECTS.
Primitive man may not have known what exactly the wind was, but he could see and feel the effects.
The gravitational field of pluto (yuggoth) caused disturbances in the orbit of nearby planets. It was the realization that these orbits were disturbed that caused scientists to seek an answer; the existence of a new planet was postulated, the orbit of the unseen planet was calculated, and when scientists looked at the piece of sky in which pluto was predicted to lie, there it was!
Before we can build any GhostBuster-like etherial containment fields, we first need to see EVIDENCE of the existence of something previously unknown. As has already been explained, claims of paranormal activity fall into two categories: 1) non-reproducable or 2) fraudulent.
A couple of years ago cryptozoologists were fascinated by reports of a new invisible life-form that came to be known as "Rods". After a few months of serious inquiry it was demonstrated that these "rods" were the product of the ideosyncracies of video cameras and the motion of moths in flight. The "rods" were ordinary moths imaged on video.
Personally, I believe there are things we don't know about the world we live in. The coelacanth is a fish once thought to be extinct, until one was caught in a fisherman's net: now we have videos of them in their native environment. No one has ever seen a giant squid alive in it's native environment; yet the existence of dead giant squids suggests strongly that there must be live ones somewhere. There are lifeforms living near deep sea thermal vents that use electron transport mechanisms (energy systems) very different from ours.
Something new will be discovered tomorrow, but given that there is no evidence for the existence of a spiritual realm, I doubt that it will be one of those discoveries. Fakes and frauds playing on our emotions and dreams will continue to be exposed, however.
