Homes were evacuated on Sylvan Knoll Road in Stamford on Monday morning after a maintenance worker found an old military device in a basement on Tuesday morning.
Residents were allowed back into their houses after the bomb squad determined that the item was not harmful.
Officials said the 25-pound military ordnance was possibly from the World War II era and was a practice round used it only for practice.
According to the Mechanical and Chemical Industry Corporation, this might have been an aircraft practice bomb.
