The two holes seen in the ceiling of the Rose Reading Room at the New York Public Library.

That’s one pricey misstep.

An electrician accidentally stuck his foot through a $12 million ceiling in the main branch of the New York Public Library — twice — sending chunks of plaster raining down near visitors Tuesday afternoon.

No one was injured in the mishap inside the Rose Main Reading Room, which left football-sized holes in the vaunted “ceiling, whose pricey repair was prompted in 2014 when a decorative rosette came crashing down.

Stunned witnesses described seeing “someone’s foot poking through” the ornate, 52-foot-high ceiling and “what looked like a tool on a string being pulled back up” at around 1:30 p.m. Tuesday.

Brooklyn writer Ada Calhoun, 41, who was working on a magazine article at the time, said the sound of the plaster cracking and hitting the floor was so loud she heard it over rock music playing on her headphones.

“There was a loud cracking noise followed by a crash,” she said. “I took my headphones out, and everybody turned, and there was a hole in the ceiling in the visitor part, and on the ground I could see some debris.”

Library spokeswoman Angela Montefinise blamed the incident on an electrical contractor working in a void between the ceiling and the roof. The electrician “lost his footing and accidentally punctured the ceiling, causing two small pieces of plaster to fall” as he repeatedly tried to get up, according to Montefinise.

He was saved from crashing through the ceiling to his likely doom by metal bars that crisscross the ceiling, she noted.

“The ceiling was inspected, deemed safe, and the room was reopened 30 minutes later,” she said.

It was unclear how much it would cost to repair the damage.

The company that employs the worker, Campbell & Dawes of Kew Gardens, didn’t return a call seeking comment.

The Rose and adjacent Bill Blass Public Catalog rooms were both closed for inspections after the rosette fell overnight in May 2014. But that led to an extensive restoration process that included reinforcing all 900 plaster elements with steel cables, recreating a ceiling mural in the catalog room and renovating the reading room’s chandeliers.