A schoolkid’s goofy model of a TV cartoon robot caused a panic that shut down parts of Metro-North’s New Haven line to Connecticut for three hours Friday morning.

The model of “Bender” from the Comedy Central show “Futurama” — a cardboard figure with a clock face and comical angry eyes and grin — was accidentally left on a bridge over the tracks near the Fairfield station.

A town street sweep­er saw it at about 5:30 a.m. and alerted Fairfield cops, who called in MTA police and a State Police bomb squad and helicopter to seal off nearby streets and investigate.

Metro-North and Amtrak suspended service between New Haven and Stamford, leaving thousands of fuming commuters stranded or scrambling to find another way to their destinations.

It took cops nearly three hours to realize that the “suspicious package” was only a harmless model of the robot — described on the show as an “alcoholic, whore-mongering, chain-smoking gambler.”

Cops later identified the culprit as a seventh-grader at nearby Tomlinson Middle School.

The embarrassed boy told his family that he left the model, a school art project, behind while rearranging his backpack, Fairfield police said.

“The child inadvertently left the item in the vicinity of the bridge with the intent of returning to retrieve [it],’’ Deputy Chief Chris Lyddy said. “There was no malicious intent.’’

Lt. James Perez described the unidentified student as “understandingly upset at the outcome.”

Ironically, the whole episode could have been avoided if a local commuter activist who had seen the model the night before had told someone.

“I feel stupid,’’ a sheepish Mitchell Fuchs of the Connecticut Commuter Action group told the Connecticut Post. “I even remember thinking, ‘I hope my hand doesn’t blow off’ when I reached into the box. But then I saw it was empty and figured someone just left it there.”