Zak Bagans' 'Ghost Adventures' Costar Has Run-In with Figure in Desert

Zak Bagans and his crew are often chasing ghosts on TV -- but over the weekend, the roles were reversed ... with a phantom appearing to go after his partner when cameras weren't rolling.

The "Ghost Adventures" host tells us his cohost on the show, Jay Wasley, believes, hand-over-heart, he and his girlfriend had a real-life run-in with a paranormal figure Saturday night while they were road-tripping through the Nevada desert.

We're told Jay and his GF were stargazing that night in Tonopah -- one the best places in the country for that sort of thing -- and while JW was lying down with his dog, his girlfriend snapped pics for a time-lapse, trying to capture the star-filled sky and scenery around him.

While they didn't notice anything weird at first ... a second look gave them pause, as we're told they stumbled across this one photo where something appears to materialize over Jay.

Zak says what he sees -- and what Jay and his gf certainly believe they saw -- is some kind of shadowy humanoid figure ... with eyes, a mouth, arms and even hands appearing in the photograph (which we're told is NOT altered at all). 😱

The would-be apparition seems to be floating above Jay ... if only for a moment, as it only appears in a single frame of the many photos his gf took at that time.

Still, we're told it gave Jay the creeps, almost like he was taking his work on the road with him! Zak tells us he and Jay believe it's authentic and a legit ghost sighting ... and they challenge anyone in tech, or otherwise, to debunk it, if they think it's BS.