An explosive device was found Monday in the mailbox of billionaire George Soros’ New York house, according to police.

An employee at the Katonah home opened a package that had been placed in the mailbox and found the device, Bedford police said.

The employee placed the package in a wooded area near the home, which is one of three listed for the wealthy investor in that area of the town, and called the cops around 3:45 p.m.

The device had black powder on it, law enforcement sources told The Post.

According to the New York Times, which first reported the story, bomb squad technicians were able to “proactively” detonate the device and it didn’t explode on its own.

The 88-year-old Holocaust survivor wasn’t home at the time.

The FBI is investigating. They said there is no threat to public safety.

Soros, a businessman and philanthropist, is well known as a lightning rod for criticism from those who oppose his strong financial support for Democratic candidates and progressive causes.