Police lights flashing in your rearview mirror is rarely, if ever, a good sign, right?

Unless the patrol car pulling you over happens to be carrying Santa Claus, aka Suffolk County Police Officer Alberto Acevedo.

With fellow officer Brianne Yarborough operating their sleigh, er, patrol car, Acevedo passed out Target gift cards and candy to unsuspecting motorists during about a half-dozen traffic stops in Patchogue over the weekend, police said Tuesday.

“Good morning, I’m Santa Claus from the Fifth Precinct,” Acevedo greeted drivers and passengers, several of whom were youngsters.

In an instant, faces originally showing alarm lit up with smiles.

The two officers looked specifically to pull over vehicles with families, police said.

“I was getting yelled at, at first, then I noticed it was Santa,” said John Campbell of Patchogue as his son, Declan, licked a candy cane in the back seat.

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Campbell said the holiday traffic stop made his family happy.

“It’s a good start to Christmas, and with our son in the car, it’s great,” he said.

The stops were fun for the officers, too.

“For once it’s a great feeling to pull cars over,” Yarborough said. “A lot of times we pull them over and we’re the bearer of bad news.

“To see the faces of these children, you can’t beat that.”

Acevedo said the Target gift cards were just a way to say merry Christmas from Suffolk police.

“It’s nice to see the kids eyes light up . . . it’s fantastic.”