One candidate on the ballot this year doesn’t need a briefing book to study Tehran terror: he was held captive by the Islamic Republic for 444 days.

Kevin Hermening, a Wisconsin Republican running for the House, was just a 20-year-old Marine senior sergeant when he became one of the initial 66 Americans taken hostage by Iran in November 1979.

He and other troops used tear gas in a bid to keep Iranians from storming the US embassy in Tehran.

“There were 10 of us who managed to hold out for an additional four hours, and during that time we were destroying classified materials and documents and computer gear, satellite equipment,” said Hermening, now 66.

They surrendered after Iranians showed them State Department security official Al Golacinski, who had been handcuffed and blindfolded with a gas mask bag over his head.

“They had his hands cuffed behind his back, and about 25 guys with automatic weapons trained on him, and a noose around his neck,” Hermening recalled.

“And they threatened to throw his body out of the second story window and hang him to death if we didn’t open the door within 10 minutes,” he said.

At that point, he says, CIA station chief Thomas Ahern made the decision to open the vault where they were ensconced.

Hermening was in solitary confinement for 43 days, held in a 5×10 room, handcuffed and blindfolded at first.

His Iranian captors, who released 14 hostages within the first few weeks, didn’t believe Hermening was a Marine, because he was out of his military uniform when they stormed the building.

“They kept me separated because there was a long period of time where they didn’t believe that I was, ‘only a Marine security guard,’ ” he said.

One friend held captive saw his weight drop from 350 pounds to just 150 pounds during the ordeal. Another captive, Col. Charles Scott, “had three of his teeth busted off with rubber hoses during his interrogations.”

And the station chief, Ahern, spent an astonishing 425 days in solitary.

One friend held captive saw his weight drop from 350 pounds to just 150 pounds during the ordeal. Another captive, Col. Charles Scott, “had three of his teeth busted off with rubber hoses during his interrogations.”

“It’s nearly impossible to imagine, because for me, after just 43 days in solitary following a failed escape attempt of mine, I was already going stir crazy,” he said.

Hermening noted that a roommate in captivity, Bill Keough — a civilian who had been superintendent of the American School in Tehran — gave guidance that set him on his current course.

“He always said when we get out: Pursue your education, get involved in your community, build a life of relevance. And I’ve never forgotten those words,” he recalled.

Hermening said he could probably recite “a pretty good listing of all of the individuals or groups of people who have been maimed or killed by the Iranian regime over the years.”

He ran through some of them: Robert Levinson, a former Drug Enforcement Agency and FBI employee who disappeared inside Iran in 2007, or the 220 Marines and 13 sailors and three Army soldiers killed in the attack on their barracks in Lebanon in 1983.

Yet he is hopeful for Iran’s future even with the turmoil of a decimated regime facing relentless attacks.

“Just like it was a great day for me when I was ultimately freed along with my colleagues, I think it’ll be a great day some day … that the Iranian people are able to pursue their version of a liberal democracy, or at least moving in that direction.”