Bomb squad officers called in to blow up a suspicious package found it contained a packet of chocolate buttons and a vibrator.
Post Office staff in Hasland, Chesterfield called in police when they heard the package making a noise.
Mansfield Road was closed off for an hour and a half while the bomb squad carried out a controlled explosion.
A police spokesman said: "Officers had no way of knowing what was inside the package. But it gave us a giggle."
He added: "They had to act on the information available and had to do what they thought was right. Thankfully it was nothing more serious."