If this plot, concocted by Jonathan Bernstein, James Greer and Gregory Poirier, sounds vaguely familiar, it’s because they borrowed liberally from “The Pacifier” (2005), in which Vin Diesel played an undercover agent caring for five kids, along with bits from Arnold Schwarzenegger’s “Kindergarten Cop.”
‘The Spy Next Door’’ may be a Z-movie rip-off of “The Pacifier,’’ which was a B-movie rip-off of “Kindergarten Cop,’’ which wasn’t a grade-A idea to start with, but at the new movie’s center is a notion that’s charmingly, if not dementedly democratic: That a nerdy businessman/undercover super-agent played by action star Jackie Chan could build a loving, sustainable relationship with the suburban single mom next door played by supermodel Amber Valletta.