A “suspicious incident” at the Republican National Committee offices in West Palm Beach, Florida, last week that prompted employees to evacuate appears to be no more than a prank, officials say.

Police in the Florida city where the RNC and former President Donald Trump have offices, said three “chirping devices” were found under desks Thursday, according to a police report obtained by USA TODAY. The New York Times first reported the incident.

Employees at the time worried the less-than-2-inch-long gadgets were listening devices. Out of caution, police say about 50 people were evacuated.

Turns out, the equipment was a different kind of bug, likely intended more to annoy staff than record their conversations.

The devices that raised alarms were plastic noise makers, available for purchase on Amazon, local law enforcement said. They “beep, screech, or make a cricket sound at random intervals of 5 to 25 minutes,” the product description says. “(A) good April Fools Day prank for your friend or coworker.”

Fears of more malicious intentions weren’t unfounded, though.

The FBI confirmed last month their investigation into potential Iranian cyber agents breaching the Trump campaign’s online operations, and his opponent, Vice President Kamala Harris’, campaign revealed it was also the target of a failed hacking attempt.

Officials in the West Palm Beach police report said they do not know yet who was behind the incident last week.

The RNC and Trump campaign did not immediately respond to requests for comment.