As cautionary tales go, it’s a horror story. It’s a video titled, “The Reckoning” — something like “The Shining,” except it’s based on facts.

It stars — likely in his last role until many pages fall from a calendar as seen in old prison movies — Craig Carton.

Carton, 50, is scheduled to stand before Judge Colleen McMahon in Manhattan federal court on Friday to be sentenced for a reported $5.6 million in gambling-driven financial fraud.

Carton ran a fraudulent bulk ticket business, promising investors prime seats to big concerts, but instead spent $7 million to pay off his own gambling debts. He faces as many as 45 years in prison, though prosecutors have recommended 5-7 years.

“The Reckoning” was apparently shot and edited six weeks ago, and was to be released to the public — as per Carton’s wishes — following Friday’s sentencing. If he prefers a jailhouse confession to a preemptive one designed to curry the court’s sympathy, that’s good on him. Either way, he’s headed to prison, no one left to con.

But I’m not bound by his rumored wishes. Besides, it’s a powerful five-minute video. And even the most cynical among us might agree that Carton’s nightmare is valuable.

For 10 years, his ratings-blessed WFAN act, the kind of morning-drive show radio executives crave and reward — profane put-down artistry, defamations, toilet humor, adolescent sexual cracks — met and perhaps exceeded his terms of engagement. He’d cut people up for fun, sport and ratings. And he’d toss in some charity work.

Carton was good at being Don Imus’ replacement, rising to $2 million per year before the FBI arrived.

But “The Reckoning” is less about Carton than it’s about a widely misunderstood disease, one dismissed only as a symptom of greed as opposed to insanity, an affliction that can only grow with politicians’ and sports’ institutionalized eagerness for everyone to bet everything, a business designed for investors — constituents, sports fans — to lose their money.

The video opens with a show and tell. Carton: “My 7-year-old son went back to school after the summer. The teacher said, ‘I want you to draw for me your favorite places to visit.’

“He drew Atlantis, Hollywood Hard Rock and the Borgata — three casinos. That’s not normal for a 7-year-old. That’s the first time I really looked in the mirror and said, ‘You’ve got a problem.’”

Next, shots of the front-page headlines and video of TV news stories about his arrest, followed by his on-air claims that he’s a “blackjack savant” who can guarantee huge profits. He actually believed it. But not for long.

“Four people — two I never even met to this day — advanced me upwards of a million dollars” with the promise of returning a quick five or ten percent profit on their dough and his genius, as if he needed to share his take.

“I borrowed over $30 million to gamble with. Helicopters, private jets, vacations. I had it all at my disposal because I was wagering obscene amounts of money.

“And I didn’t care. I had a huge ego when it came to my ability to play blackjack … I was wagering 10, 20 thousand dollars a hand just a few hours before I was supposed to do a radio show.

“If I was drinking, you could tell I was drinking. Drugs? You could tell I was on drugs. Gambling? There was no way to tell.”

“Harrah’s in Atlantic City. They allowed me to wager five hands at $25,000 a hand, at once. Obscene. I won $4 million in three days and didn’t tell a single person. Didn’t enjoy it, didn’t buy anything with it.

“Two weeks later, I lost $700,000. You end up living in an isolated, introverted world of secrets. And that’s what I did, until I couldn’t anymore.”

For more than 30 years, I’ve been studying and writing about addictive gambling and its frequent twin addictions, and I seldom fail to hear the word “spiral” from the afflicted. It’s never an upward spiral. In the video, Carton says he was helpless, caught in “a deep dark spiral.”

He speaks matter-of-factly, like Joe Friday: “Sept 6, 2017. It was 3:50 in the morning. I was leaving my apartment to go to work … There’s a woman coming up the steps. She says, ‘Are you Craig Carton?’ I said, ‘Yes.’ She said, ‘FBI, you’re under arrest.’

“And that was my day of reckoning, and it has all gone downhill since.”

On that morning and the next, Carton’s co-host Boomer Esiason , having reported his partner’s arrest, lent his voice, name and reputation to a commercial for a young male-targeted sports gambling operation.

More from Carton: “At the time of this taping I’m awaiting sentencing … I threw it all away. It has cost me everything. My relationship with my wife, who I’m legally separated from now. I’m bankrupt. I’m about to be homeless.”

And he has four kids.

“My family had no idea that I was leaving the apartment at midnight, getting on a helicopter or driving to casinos.”

Carton apparently entered Gamblers Anonymous. “The Reckoning,” which I surmise will be released to the public after Friday’s sentencing, concludes with the personalized preamble to GA testimonies:

“My name is Craig and I’m a compulsive gambler. Last bet, June 22, 2018.”