The apparent finding comes in a two-part episode about the abandoned and infamous Los Feliz Murder House, where Dr. Harold Perelson murdered his wife in 1959 with a ball-peen hammer and severely beat his daughter before killing himself.

The equipment the 'GA' crew used in the creepy mansion makes it all the more fascinating.

Zak Bagans tells TMZ the ghost chair was captured during a moment where chairs were the focus of an experiment -- "Everybody had a chair that was set on different floors of the house, and we connected everybody’s energy together using these chairs in a summoning experiment."

His take on what you're seeing here is, "It’s as if Dr. Perelson, who we called upon, literally pulled up a chair himself to join our experiment."

They used a method called LiDAR which uses a laser to scan objects or surfaces, by measuring the time it takes for the reflected light to bounce back ... basically, 3-D laser scanning.

The chair seemed to appear and then disappear on the laser scan, despite there being no seat in the actual scanned room.

The hunters stress the fact that the equipment is down to the "millimeter in accuracy" of scanning actual objects ... which makes said ghost chair like nothing they've ever seen before.

Zak says "This is one of the most astounding pieces of scientific evidence we have ever captured in the history of 'Ghost Adventures,' made even stronger due to the fact that it was captured by an accredited third-party LiDAR scanning company."