'Ghost Hunters' Star Supports Tucker Carlson's Demon Attack Story

Tucker Carlson claims he was once violently attacked by a demon as he slept ... and despite all the naysayers ... one paranormal expert absolutely believes him.

Here's the deal ... the popular TV personality appeared in the new documentary, "Christianities?" ... where he revealed he'd once woken up to find huge claw marks on his sides and shoulder -- ones that didn't match his own hands. He says in no uncertain terms ... demon attack!

"Ghost Hunters" star Steve Gonsalves tells TMZ ... those quick with the jokes and totally dismissive should slow their roll ... 'cause something very well could have happened to the dude beyond typical comprehension.

The renowned paranormal investigator says evil presences can legit enter the human body and sometimes do some real harm ... but a true blue -- actually, red -- demon encounter is exceptionally rare.

Fact of the matter is ... as SG tells us, Tucker seems to be honest about the encounter ... and because it is something that Steve has heard before from others -- and even experienced personally -- he totally believes the guy.

As for the skeptics, SG says all good ... it's natural for people to question what they don't believe or fully understand ... just as long as they are not jerks about people who do. And, TC being a celeb helps spread the word and entice curiosity.

Sounds like Tucker ain't necessarily fibbing ... but he doesn't need a visit from 2 priests ... yet.