'Ghost Adventures' Zak Bagans -- Snatches Pot the Real 'Psycho' Used to Collect Body Parts

"Ghost Adventures" star Zak Bagans just scored a disgusting and evil souvenir used by the real life killer who became the inspiration for "Psycho" and a bunch of other Hollywood serial killers.

Ed Gein was a Wisconsin man who infamously mutilated his victim's body parts in the 1950s, and fashioned their skin into tiny masks, gloves, and furniture. If it sounds familiar -- Leatherface from "The Texas Chainsaw Massacre" ... Buffalo Bill from "The Silence of the Lambs" and Norman Bates were all based on Gein.

So, Bagans just dropped $2,800 at auction to take possession of the 25 gallon cauldron Gein used to discard his victims' entrails when he gutted them. The thing had been sitting in a Wisconsin woman's home -- used as a flower pot -- ever since Gein's 1984 death in prison.

When she died ... her son (wisely) believed the cauldron was cursed, and wanted it gone ... so now it's Bagans' headache.