JOHN Jamelske, the twisted Syracuse rapist who kept women chained up in his underground “dungeon” over a 15-year period, says he thought he’d only get a slap on the wrist for what he did.

“I’m thinking, you know, maybe I’m gonna get some community service or something of that nature for, you know, a little bit of unlawful imprisonment,” Jamelske tells “Dateline’s” Rob Stafford in an interview airing Friday.

Jamelske pleaded guilty to kidnapping last summer and was sentenced to 18 years to life in prison for secretly imprisoning women in a makeshift dungeon on his property – then holding them for months or years as his sex slaves.

Jamelske also calls his dungeon – a series of small, windowless, concrete rooms with no plumbing – “absolutely beautiful,” and says he wouldn’t have minded being held captive down there.

The interview airs Friday night.