This is spooky, even for Zak Bagans ... he's the new owner of John Wayne Gacy's prison art, a potentially haunted haul which includes a creepy Killer Clown self-portrait.
The "Ghost Adventures" star tells TMZ ... he bought a bunch of the serial killer's paintings from prison, along with some letters Gacy sent to his stepdaughter ... and the clown themes are not unexpected but still striking.
Infamously known as the Killer Clown, Gacy was executed back in 1994 after being convicted of murdering 33 young men and boys in the '70s, burying most of the corpses in a crawl space under his Chicago-area home.
As you can see, Gacy painted himself as a clown while behind bars and sent the self-portrait to his stepdaughter, Tammy Hoff, along with letters decorated with clown stickers.
Zak tells us Tammy, who lives near his Haunted Museum in Vegas, recently contacted him about selling the items. Zak says Tammy lived with Gacy in Illinois during the murders, but didn't know her stepfather was a serial killer.
In addition to the weird art and letters, Zak also bought one of the last Polaroids Gacy snapped, plus his last pack of cigarettes before being executed.
Zak says the Gacy art and letters piqued his interest because they make Gacy seem like a loving stepfather, despite murdering 33 people. The items are gonna be displayed in his museum's true crime exhibit, alongside with other stuff from serial killers.