Top, the first ballot box arrives Tuesday at Cambridge's Senior Center for the start of a citywide election count. Above, Shawn Ryan, an out-of-town volunteer for the Service Employees International Union, watches over a Majorie Decker campaign poster at the Russell Apartments polling place in Porter Square. (Photos: Marc Levy)

Voting has been light today, or at least average for a municipal election, poll workers and wardens said, save for one thing: the number of write-in votes is at least double what it’s been in years past.

That’s certainly the Marjorie Decker factor at work, since the incumbent City Councillor — first elected in 1999 — missed a filing deadline and had no choice but to run as a write-in candidate. In the past she’s had the support of celebrities such as historian Howard Zinn and former high school classmates Matt Damon and Ben Affleck. This time she had the support of the Service Employees International Union, which had members from as far away as Brockton and Framingham at polling places today, holding signs and passing out stickers for voters to affix to ballots. Some of Decker’s signs are huge — the size of cars, if laid on the ground.

The effort appears to be working.

At the Vernon Hall Nursing Home on Dana Street, the polling place for Precinct 6-2, warden Sharon Edey said voting throughout the day had been average, meaning light, save for the write-ins. “We’re heavy in write-ins,” she said. “They’re up more than 100 percent,” meaning they’re more than doubled.

Not far away at City Hall, the polling place for Precinct 4-2, warden Grace Bowen confirmed the unprecedented surge in write-ins at least in the six or seven election cycles she’s worked.

“I’ve never seen an intentional write-in campaign,” she said. “Somebody — not us — is going to have a good time counting those write-in ballots.” (Otherwise, she said, she didn’t think there’d been a line to vote all day. “It’s no-wait voting,” she said.)

Precincts elsewhere also confirmed voting was low, even with bake sales attached, such as at the Maria L. Baldwin School, where voting was taking place for precincts 7-1 and 7-2, and even in student areas where challenger Leland Cheung was thought to have strength. Precincts closest to Harvard saw no surge in student participation.

Polling places were also quiet. Police at the Senior Center, where the ballots will be counted tonight, said they knew of no campaign-related incidents being reported. The only controversy of which they were aware was of extra Decker stickers being affixed inside voting booths.

While there seems to be no Cheung factor at work, the Decker factor ensures there will be no decisive results tonight. The write-ins will be looked at Wednesday and are sure to upset whatever results are determined with tonight’s count.

It seems to validate Councillor Craig Kelley’s decision to party on Cedar Street, whatever happens, instead of haunting the Senior Center counting process for a hint of what’s to happen.

“We had a plan and we followed that plan to run a focused campaign and show people you can get elected to the City Council without spending 30, 40, 50, $60,000,” he said from in front of the Baldwin school, referring to himself and his wife. Now that plan has him celebrating with supporters instead of worrying about the end vote.

At 8:35 p.m., the first ballot box arrived, for Precinct 1-2, and the citywide count began.