With “The Stranger in My Home” Sophia Bush and Chris Carmack know that they’ve made one humdinger of a multi-layered thriller.

Parents in an affluent suburb, both with teenage daughters, their lives are upended when Carmack’s Tom Truby shows up at Ali’s doorstep.

“Tom arrives,” Carmack, 44, said in a joint Zoom interview, “and presents a situation for these two families that throws everybody for a loop. All of a sudden, everyone’s reality is completely unbalanced — nobody knows what to make of it!

“Everyone is going through very high emotions dealing with Tom’s idea: Their 16-year-old daughters were switched at birth.

“Now, the question is: ‘What is family? Is this my daughter? Is that my daughter? I don’t even know.’

“There’s something very natural about everyone working through the situation in their own way. Particularly, when we see Tom, we have to give him the benefit of the doubt because he is working through something very difficult.”

That benefit disappears when we discover he’s unbalanced in more ways than just how the situation has unsettled him.

“Playing Tom,” Carmack added, “was one of the funnest roles I’ve ever gotten to play.”

“Chris and I are so grateful to have such wonderful source material,” said Bush, who plays tormented Ali. “Adele Parks wrote this incredibly nuanced, rich, terrifying, exhilarating story and her adapting that into a screenplay really adrenalized the whole thing and gave us so much to work with.”

Bush, 42, calls Ali “relentless in the way she loves her kid and it fuels her, for sure. It’s an interesting thing to play a woman that sees and knows what’s going on with her kid so well, then finds out there’s so much that she doesn’t know at all.

“It really adds to the nervousness. Particularly because she’s been through it before, she knows what might be coming. Certainly, she’s not a perfect hero. She’s overwhelmed and scared and pushed to the edge.”

As the two families try to grasp what happened 16 years ago, police are called and complications — with violence, threats, mean girls and a disappearance — ensue.

“Because every character here has a secret,” Carmack noted, “everybody is suspicious, right?

“What was also wonderful with this story,” he continued, “is that these are relative strangers. But they are sharing the most intimate experience upon first meeting.

“The cognitive dissonance of that sort of emotional whiplash allowed us to constantly ‘hit the gas’ and then pull back.

“Throughout the story, it enables us as actors to not really know where we stand with each other. That feeds the tension.”

“The Stranger in My Home” streams on digital June 24