HINGHAM — His wife spotted the ad in the local newspaper 10 years ago. A nearby elementary school needed a custodian.

“Why don’t you go for it?’’ Beth McDaid asked her husband, Seamus. And so he did.

Seamus McDaid was among more than three dozen candidates for that job. But something about him — perhaps the glowing letters of recommendation attesting to his integrity and work ethic — grabbed the hiring panel’s interest.

In early April 2006, he became the head custodian at Hingham’s Plymouth River Elementary School.

At first, it seemed a perfect match. “A lot of hard work,’’ said McDaid, a 52-year-old native of County Donegal, Ireland, where his father was a farmer. “But I didn’t mind. I’m a good hard worker.’’

His performance reviews said so. The principal was impressed with his work, how clean the classrooms were, how sharp the grounds looked.

“His work ethic and response to teacher requests is outstanding,’’ principal Chuck Cormier wrote in May 2007. “The cleanliness of the building and the maintenance of its grounds has improved dramatically since his employment at PRS.’’

Gold-plated reviews like that did not surprise those who know what kind of worker McDaid is. Ray Riddle hired him to manage a vending and food service company he owned in the year before McDaid left to take the custodian’s job.

“I started getting calls from people who were wondering what happened to Seamus,’’ Riddle said. “They told me, ‘If you fired him, we’re not going to be happy with you.’?’’ Fire him? Never. Under McDaid, vending sales increased. Complaints decreased. Customers loved his personality, his honesty, his integrity.

Some staff members of Plymouth River Elementary School loved that, too. McDaid has the letters to prove it.

A technology chief called him conscientious, cooperative, agreeable. One teacher praised his cheery demeanor and how he left the cafeteria spotless after lunchtime. Just before Thanksgiving last year, a teacher reported that one of her kids had somehow kicked a sneaker onto the school’s roof. McDaid retrieved it, no problem. “Friendly, supportive, and helpful,’’ she called him.

But by last Thanksgiving, Seamus McDaid was no longer collecting rave job reviews. Those who once lauded his “solid work ethic’’ now had complaints.

They deemed him inflexible. When he cleaned the cafeteria floors after lunch, the machine disturbed a nearby music class. When he rushed in to unclog a girls bathroom toilet, he didn’t prop the door open even though the lavatory was empty.

In January, he was called on the carpet for what his supervisors called his lackadaisical response to a crayon melting on a radiator, and a too-slow effort to set up the cafe for a speaker. “This behavior and work performance is not isolated, and comes against a significant history of behavioral and performance issues,’’ Cormier and other administrators wrote to McDaid last month.

There was a big meeting. Lawyers were involved. And now, McDaid faces a demotion, a healthy pay cut, a transfer to nights and — perhaps — termination.

“They’ve taken minor infractions that happen every day in a school setting and made them into major infractions in order to demote or discharge him,’’ Steve Rosenberg, McDaid’s attorney, told me this week. “They should have better lines of communication.’’

Cormier declined to speak with me when I visited him. Hingham Schools Superintendent Dorothy Galo told me: “Seamus has a lot of wonderful points, but there are a lot of things that go into an assessment of job performance.’’

Exactly. A reputation and a livelihood are at stake. The totality of Seamus McDaid’s work should be weighed.

“I know I am not perfect,’’ he’s told his superiors. “No one is!’’

Hingham schools promise to “treat each other with care and respect.’’

Surely that applies to the custodian, who makes his school sparkle but now can’t sleep at night.

Thomas Farragher is a Globe columnist. He can reached at thomas.farragher@globe.com.