When you’re mute, nobody can hear you scream.

That’s the horror hook for “The Djinn,” a generic but well-executed tale of a little boy who makes the right wish of the wrong genie.

The standard ingredients of such a tale are almost laughably over-familiar. A tweenage kid left alone in an apartment by his “double shift” all-night DJ dad. Mom “left” because of the child’s mutism. The previous tenant “died here.”

And what did the deceased leave behind, other than a framed photo of himself? A version of a “Book of Shadows.” Because of course he did.

That’s what young Dylan (Ezra Dewey, quite good) stumbles across when older-than-average Dad (Rob Brownstein) isn’t around. Dad may reassure the kid that “You’re perfect the way you are,” but Dylan has his doubts.

Once he’s opened the burlap wrapping sealed with prayer beads, you know what he’s looking for in the Book’s index — “Wish of Desire.” And we all know what he’ll be wishing for.

Not that he isn’t warned — “Beware the djinn’s toll, for the gifts that you seek may cost your soul.” But kids, am I right?

The spooky stuff that starts happening, after Dylan’s ASL’d the incantation into a mirror, includes bumps and thumps, a boombox radio that tunes itself (the setting is 1989, for no real reason), a TV that goes to static and demonic reflections Dylan sees on the screen when the set turns itself off.

Inky smoke invades the apartment, the light turns crimson and suddenly the kid is being chased-stalked (by the camera). He’s locked-in, the cordless phone is dead and Dylan is scared out of his wits.

All this is going on, chased by a “presence” which one moment might be a dead murderer killed after an escape attempt, another the dead previous tenant of the apartment or even Dylan’s sad, disturbed mother (Tevy Poe), terrifying the child when he should be pissed.

Because Dylan’s getting the djinn’s threatened “side effects,” but doesn’t get the promised voice.

Dewey, who looks a little like the young Joseph Gordon Levitt, conveys plenty of alarm and terror at what’s confronting him. Dylan fights back on a very basic level, and he has a chance because, as any movie hellbent on hauling out a hoary “Book of Shadows” suggests, there are “rules,” things that allow him to compete, “until midnight” escape clauses.

This isn’t anybody’s idea of a new horror classic. But “The Djinn” takes a basic story and delivers the basic jolts and frights we expect from it. No more, no less.

MPA Rating: R for some disturbing violence

Cast: Ezra Dewey, Rob Brownstein, Tevy Poe

Credits: Scripted and directed by David Charbonier, Justin Powell. An IFC Midnight release.

Running time: 1:21