If you enjoyed watching the trailer for “Other Mommy” during every multiplex outing this summer, you’ll get an extended dose of its freneticism during the actual film — right down to an opening title card that appears letter-by-letter while intercut with choppy action. From director Rob Savage, and adapted from the horror novel “Incidents Around the House,” the finished product is among the most limp and ineffectual works to grace the screen this year, misfiring in every direction, including and especially its tone.

It plays, at times, as though a horror comedy in the vein of Sam Raimi had been recut at the 11th hour to resemble a straightforward scarefest, down to missing chunks one imagines had been ripped out by hand. The saga begins with what feels like a second act and continues in a constant state of climax, with an endless litany of numbing jump scares that grow quickly stale, since they all unfold pretty much the same way. More often than not, the camera tracks around an unsuspecting character in a circle, revealing from behind them the eponymous Other Mommy (Jessica Chastain, delivering a grin that’s more goofy than unsettling), a demonic being posing little actual threat. The effort at trying to make this work a hundred different ways would be adorable if it weren’t so grating.

When the story opens, adolescent protagonist Bela (Arabella Olivia Clark) is already familiar with the creature hiding in her bedroom, who takes the form of her mother Ursula (Chastain). It isn’t long before her father Russell (Jay Duplass) catches a glimpse of the monster too, when it taunts them in the kitchen one morning, leading to a straight-faced premise where everyone readily accepts that there’s a sinister copy of Ursula hiding somewhere in their home, and contorting her body in the shape of a swastika for no real reason. When most other horror movies feature skeptical naysayers, they do so for the sake of building tension and intrigue; “Other Mommy” doesn’t seem interested in these things.

Despite gazing at the ghostly presence in full, Bela’s parents don’t seem all that spooked, even when the young girl is tossed around like a rag doll during an anniversary gathering at their home. No human character seems to behave like a real person, and the Other Mommy is merely an impish rogue along the lines of Pennywise the Clown, minus the child eating. It’s a movie of psychological pranks involving ball pits, wonky gravity, and a CGI Chastain alternatingly melting like the Batman villain Clayface and flailing about like an inflatable tube man outside a secondhand car dealership. All the while, there’s seldom a sense of scale or proximity to put any of this into physical perspective.

There are the bare bones of a story and theme if you squint, in that Bela suspects her mother of having an affair. So, the idea that Ursula is not who she appears to be makes for a worthwhile entry point into a tale of an eerie, dead-eyed copy — at least in theory. In practice, this mischievous presence ping-pongs between maternal lies and the wholesale impersonation of other people. This may be in keeping with the novel, but little of the movie’s condensed, 94-minute runtime feels guided by any visual or emotional idea; it all but abandons the “Mommy” half of its premise before long.

In addition, each of the three leads seems to belong to a markedly different movie. Chastain goes for broke with melodrama as both the real and fake Mommies. Clark, although she plays younger and more naive than her actual age, maintains a captivating, naturalistic presence, until she seems to get exhausted by the premise (who can blame her?) And Duplass, with his “aw, shucks” demeanor, reads like a broad caricature out of a comedy sketch. It’s all over the place, and it isn’t made much better by the fact that scenes appear to begin and end at random without much flow or rhythm — a seeming result of “Other Mommy” being cut within an inch of its life.

In the most basic sense, a film in which supernatural scares arise courtesy of negative space ought to at least have thoughtful framing, but the endless series of startles arrive with the same weight and energy as the fake outs. Tension dissipates no matter who or what jumps out from darkened spaces, as the movie veers between physical dangers and imaginary sequences as Chastain’s spiritual entity occupies young Bela’s attention like an annoying, persistent daydream. That’s about all that “Other Mommy” is to its audience too: an annoyance to be handwaved, rather than tension or meaning to be confronted at any stage. Feel free to keep your arms and legs outside the ride; it’s not going anywhere.