Rupert Grint is a big fan of reading about crazy conspiracy theories

Rupert Grint can play the didgeridoo. The “Harry Potter” co-star is a big music fan, but he says he’s never had the patience for the guitar. Still, he’s tried his hand at the accordion and, after suddenly acquiring one, the drone-y Australian wind instrument.

“It’s quite hard to make a noise on it if you don’t know to do the circular breathing thing. I was just determined to do it,” Grint tells us over the phone from England. Still, its uses are limited. “It’s not an instrument you can do a lot with. There aren’t many songs that call for it.”

Grint, 27, could spend the rest of his life doing nothing but learning to play strange instruments. After all, he devoted 13 years to playing Ron Weasley, the most flabbergasted of the “Harry Potter” films’ central trio. Instread, like his co-stars, Daniel Radcliffe and Emma Watson, he’s kept up the acting, taking roles that are very un-Hogwarts. He’s done dramas (“Cherrybomb”) and a war film (“Into the White”), played punk reprobate Cheetah Chrome in “CBGB” and performed Off-Broadway in Terrence McNally’s “It’s Only a Play.”

His new film “Moonwalkers” is also very much outside the Potter wheelhouse. Grint plays Jonny, a never-was London rock manager in 1969 who stumbles into a plan to create a fake film of the Apollo 11 moon landing, in case the real mission is a bust. This ruse winds up involving him with orgy-loving hippies, vengeful East End gangsters and a PTSD-ridden CIA heavy played by Hellboy himself, Ron Perlman.

“It’s something that doesn’t take itself too seriously, which is a rare thing,” he says of the sometimes hyperviolent comedy. “I wasn’t sure how it would turn out. It was a ridiculous hour-and-a-half. It does kind of slap you around in the face.”

Before the “Moonwalkers” script made it to him, Grint had already been a nut for conspiracy theories, or at least reading about them. “One of my favorites is that the moon is hollow,” he tells us. “NASA sent this missile up there to hit the face of the moon. The signals came back described it as ringing like a bell — like it was a hollow structure. I don’t know if it’s real. But it made me think.”

What caused him to become an avid reader of wacky theories? “I think it was probably Princess Diana,” he says, alluding to the claims made by some that there were other motives behind her death. A lot of these catch his fancy, some loonier than others. “There’s one about a reptilian race that controls all the world’s power. Every decision is made by this reptilian race. The queen is one of them. The prime minister, all the presidents — they’re all reptiles.

“The people who say this are so unwavering, and you think, just a little bit, maybe they’ve got a point. It’s just quite fun reading.”

Grint points out that making “Moonwalkers” made him wonder if claims that Apollo 11 mission was staged might have a bit of a point, maybe. “It was really easy to make the moon,” he recalls. “It looks like a set. It kind of makes you think it would have been quite easy to do it, to fake it.”

“Moonwalkers” is out-there, even when not compared to the “Potter” films. But Grint doesn’t take roles just to shock his massive fanbase, who continue to swirl around him. (He’s famous for being gracious to those who seize upon him on the street.) But he says he’s not consciously trying to mess with his image.

“There just haven’t been that many wizard roles out there,” he jokes. “It’s nice to do something different and a bit edgy. I find that a bit exciting. I like the idea of exciting people.”

He says he’d like to do something really different from Ron Weasley, though. “Something dark would be fun. Someone a bit evil. I’d enjoy that, I think,” Grint says. “I think being a ginger takes away a bit of my edge.”

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