Faith Rousso was working late in her Garden City office last week when the calls began.

At the other end of the line were enthusiastic backers of Donald Trump, calling from as far away as California and Florida to pledge their support for his White House bid.

They were confused to learn they had instead reached her adoption law practice on Long Island.

More coverageThe 1600: Follow the race for the next presidentMore coverageThe 2016 campaign: Complete coverage

Rousso estimated Thursday that the toll-free phone line intended as a resource for her clients has been inundated with hundreds of Trump-related queries over the past week.

Many supporters of the presumptive GOP presidential nominee have apparently been misdialing.

Rousso’s 800 number is one digit different from a number broadcast in TV ads by a pro-Trump political action committee.

advertisement | advertise on newsday

“The calls start around 7 o’clock at night,” she said. “You’re in your office at 7 o’clock to get your work done, and the lines start lighting up.”

Rousso, 51, of Roslyn, who said she is “not necessarily” a Trump backer, said she was at first amused by the mix-up and charmed by the Southern and other accents she heard over the phone.

Then as the calls continued throughout the evenings for several days, Rousso said she began thinking as she answered, “Please don’t tell me you’re calling to vote for Trump.”

The calls will cost her hundreds of dollars in service fees, she said. They have been so disruptive that they’ve at times tied up the line, leaving expectant mothers unable to get through to Rousso and connect with prospective adoptive parents, she said.

The callers have been trying to reach the Great America PAC, which has run ads on CNN and Fox News urging those who stand with Trump to dial an 800 number. The call includes a message from GOP operative and PAC co-chairman Ed Rollins asking for contributions to “beat Hillary Clinton in the fall” and “win this presidency for the people.”

Brent Lowder, executive director of Great America PAC, said the group’s ads have engaged 2 million Trump supporters over recent months and “caller enthusiasm” has resulted in misdials.

Lowder said in a statement that the PAC will reach out to “the affected business owner and cover her costs, even if she’s not (yet) a Trump supporter.”

Timothy Presley, 63, of Midway, Kentucky, said that after accidentally calling Rousso, he ultimately reached the right number and pledged his support, but declined to donate.

advertisement | advertise on newsday

“It said Trump needs money for his campaign, but he’s a multibillionaire,” Presley said.

“I suppose it would be an easy mistake,” the retired truck driver said of people misdialing.

Rousso called the flood of calls annoying, noting that she can’t change the number because dozens of clients hoping to adopt have posted it on their social media campaigns.

“It’s interesting that this many people would misdial,” Rousso said.