The Bedford Police Department confirmed in a statement that "an extensive investigation" was carried out in the area after "a suspicious package (was) found in the mailbox." The case has been handed over to The Joint Terrorism Task Force Division of the Federal Bureau of Investigation.
The device didn't explode and was "proactively detonated" by bomb squad technicians, according to The New York Times, which cited an unnamed law enforcement official.
The FBI said in a Twitter post it was conducting an investigation around a residence in Bedford, Westchester County.
"There is no threat to public safety, and we have no further comment at this time," the FBI said.
The incident came to light after police received a phone call on Monday about a "suspicious package found in the mailbox," according to the police statement.
It wasn't clear whether the billionaire — a frequent donor to Democratic candidates — was home at the time, the Times reported.