The mayor’s office is giving away free tickets to New York families who want to experience Gracie Mansion’s spooky Halloween makeover.

The online ticket giveaway for tours of the “haunted” mansion on the Upper East Side kicked off Friday. The grounds will be decked out for the holiday, including zombie-themed installations, skeletons and a mad scientist. Tours will take place Oct. 28-30, according to organizers.

Face painting and other kid-friendly activities will take place on the front lawn.

In the past, Mayor Bill de Blasio and first lady Chirlane McCray have joined the fete dressed in their own costumes, and the couple is confirmed to attend again this year.

The event is open only to children between six and 10 years old, and their parents or guardians. The mayor’s office will also invite children who reside in homeless shelters and foster care homes.

To join the ticket lottery log onto www.nyc.gov/GracieHalloween, or call 311 to request four free tickets. The giveaway ends Tuesday, Oct. 17.

The city will notify 1,500 winners on Oct. 24.