Park Romney says some pretty wild things.

Mormonism, he writes on the Web site, “is an insidious contemporary fraud.”

The Church of Jesus Christ of Latter-day Saints is “an American cult,” he professes.

Mitt Romney, he claims, would be conflicted in office because “obedience to the leadership of the Mormon Church is part of the covenant of the temple ordinances to which Mitt Romney is absolutely a party.”

Were you to come across a man articulating such views on a street corner, you probably would give him a wide berth and look over your shoulder to make sure he wasn’t following you.

But Park Romney, apostate Mormon, is no street-corner eccentric. He is Mitt Romney’s second cousin. Church documents and archival research done by The Post’s Lucy Shackelford trace Park’s lineage to Miles Park Romney, who is also Mitt’s great-grandfather.

The two men have never met. (Miles Park Romney had 30 children, which means Mitt Romney has scores of cousins.) And, based on what Park has been writing, he’s not likely to get a dinner invitation from Mitt anytime soon. “Gov. Romney has never heard of this person, and he doesn’t know him,” campaign spokeswoman Andrea Saul said.

Every family has wacky relatives. The difference is, when you’re running for office and you become a famous name, your relatives’ surname becomes famous too — sometimes in unwelcome ways.

As Meghan McCain can tell you, sharing a presidential candidate’s surname can be good for business. George Obama has met his half-brother Barack only twice, but he still got plenty of attention for his memoir about life in Kenya. Billy Carter used his famous name to do work for Libya when he wasn’t endorsing Billy Beer.

There were Neil Bush’s S&L problems, Roger Clinton’s cocaine and Hugh Rodham’s pardons. Lyndon Johnson reportedly kept his hard-drinking brother under Secret Service surveillance. Jacqueline Kennedy’s aunt and cousin hoarded cats, becoming the subject of a movie. Richard Nixon’s brother Donald took a bailout from Howard Hughes for his failing burger restaurant.

The Obamas have continued the tradition. When Onyango Obama was charged with drunk driving outside Boston last year, it became national news, even though the president had no contact with his “lost” Uncle Omar. Among those calling publicly for the man’s deportation: Mitt Romney. Likewise, Zeituni Onyango’s immigration case — unknown to her nephew Barack — became big news days before his election in 2008.

Park Romney, who declined to comment for this column, appears to be on this path. He self-published a book last year that mentions his older cousin. He has begun to spread word on talk radio. The gay rights group Pride in Utah has embraced him as a spokesman (“Mitt Romney’s Cousin Speaks Out”). And a person who manages his Web site claims that Park Romney was interviewed for a forthcoming BBC documentary on Mormonism and the presidential campaign.

This isn’t necessarily bad news for Mitt Romney. In most cases, family antics are more embarrassing than politically damaging. And the emergence of a “crazy cousin” might remind voters that Romney, a candidate who too often comes across as programmed, is just like the rest of us.

Some might argue that the best response to Park Romney’s anti-Mormonism is to ignore him. I have no sympathy for his message; I find his claim that Mitt Romney’s policy positions would be based on “obedience to the leadership of the Mormon church” to be preposterous.

But we don’t ignore the birther movement, anti-Semites on the left, Tea Party racists or people who encourage violence on the airwaves, and I don’t think Park Romney should be ignored either.

His sentiments, unfortunately, are not fringe views: As my Post colleague Charles Lane pointed out recently, more than one in five Americans, Democrats and Republicans alike, tell Gallup they wouldn’t vote for a Mormon presidential candidate from their own party. And now we have Newt Gingrich flirting with that segment of the population on the stump: He’s calling for a defense of “our religions” and accusing Mitt Romney of discriminating against Catholics and Jews.

For that reason, Park Romney’s use of the family name is part of something darker than Billy’s beer. The anti-Mormonism he represents should be examined in the light of day.