In what appears to be an early Halloween trick on Mayor de Blasio, someone put signs on his Park Slope house that would send shivers through any lefty politician.

One sign popped up on Hizzoner’s property saying “All Lives Matter,” while another scribbled poster urged, “Vote John Cummings,” the Republican challenger to progressive darling Alexandria Ocasio-Cortez’s congressional seat.

The signs were quickly kicked to the curb Tuesday in the left-learning neighborhood. By late morning, the Cummings poster had been run over by cars negotiating alternate side parking.

A woman who answered the door at the 11th Street home looked surprised when asked about the posters Wednesday.

“I have no idea what that is,” she said. “I have no comment.”

Tenants recently moved into the modest yellow home, which de Blasio has rented out since departing for Gracie Mansion in the summer of 2014, more than six months after taking office in his first term as mayor.

De Blasio frequently returns to his old neighborhood to visit the gym or take long walks in Prospect Park. And despite no longer living there, his home drew a crowd of teachers in September protesting the planned reopening of city schools.

The mayor claimed on his latest tax filings that the home brought in $54,000 in rent in 2019.

City Hall did not immediately return a request for comment.