Hand it to the Brits who conjured up “They’re Outside,” a never-quite-reaches-lukewarm thriller in the “found footage” “Blair Witch” mold.

They conceived a movie about a documentary shot as an unlicensed Youtube psychotherapist videoed himself trying to “cure” a woman’s agoraphobia. And yes, it looks like a film edited on a cell phone and mostly “filmed” on another. A good cell phone, but a cell phone camera nonetheless.

The cheesier-than-cheesy framing device has an academic “folklorist” intoning about “Penny film” about Youtuber Max’s “unaired episode” in which he (Tom Wheatley) attempted to treat, trick or cajole shut-in Sarah (Christine Randall) out of her Hastings, East Sussex home.

The reason the folklorist is telling us this as that the principals in this tale aren’t around, but the “Green Man” of Hastings legend might still be, a forest ghost who takes out his revenge on a society that murdered him long ago by luring victims into “The Endless Woods” and/or convincing them to do harm to themselves and others.

Sam Casserly and co-director (and sole credited screenwriter) Airell Anthony Hayles serve up a scheme within a plot within an ex post facto “film” that includes outtakes from Max’s “Psychology: Inside Out” Youtube channel — mostly Max presenting, meeting Sarah and interviewing her friend Penny (Emily Booth) while Max’s girlfriend Nicole (Nicole Miners) gets it all on tape.

But there’s also animation — expressionistic drawings used to flesh out the “Green Man” legend (we see a parade including him, part of a Halloween festival celebrating him) — “video diary” entries, CCTV footage and interviews with Max’s parents.

And the opening scene of the film has a weeping woman with a knife telling us “These are my last words…on camera.”

So something bad happened, something that went beyond Sarah’s fear of anything outside her house and the sleepwalking that’s one of the manifestations of her troubled mind.

But as Max plunges into this “case” for his Youtube fans, his asides to the camera tell us he not only doesn’t “believe in phantom (door) knocks,” he’s wondering about the authenticity of this woman he’s trying to “help,” and what she and her friend “Penny” might be selling.

“She’s certainly trying to get me to believe in this nonsense.”

While movie malnutrition isn’t a cardinal sin — many an indie film betrays its budgetary shortcomings and still comes off — here it’s a grating tune-out from the start.

Sarah is meant to be an America, and the performance of her is a case study in how mastering an American accent isn’t the easiest skill in a British actress’s toolkit.

“They’re Outside” is never the least bit frightening. The “gotchas” don’t play and the vibe is never creepy enough to set up a decent “gotcha” moment.

And you can’t lay much of that at the feet of the cast. The reason this doesn’t make much sense, that it’s dull, dumb and hard-to-follow/complicated at the same time, is the scatterbrained screenplay and the way it’s acted, directed and edited onto the screen.

The little snippets of animation are chilling, the “parade” samples and the various pieces of footage meant to be from Max’s show and Penny’s “documentary” undercut that and never jell into anything that manages to be suspenseful.

And the “Green Man” as an entity never gets his due as a “boogeyman” of legend, reality or otherwise.

Rating: unrated, some profanity

Cast: Christine Randall, Tom Wheatley, Emily Booth, Nicole Miners

Credits: Directed by Sam Casserly and Airell Anthony Hayles, scripted by Airell Anthony Hayles. A Terror Films release.

Running time: 1:23