The incident began at around 7:00 p.m. on Ferncliff Road when authorities say a realtor was about to show a home that was up for sale to a couple.
When he opened the door to the home, he noticed a man with a mask operating what the realtor believed was a meth lab.
The realtor told authorities he smelled a strong chemical odor.
Not wanting to take any chances, police evacuated 15 homes in the area and sent equipment and personnel to investigate.
The New Castle County Hazmat Decon Team and the State of the Delaware Hazmat Team responded to the scene.
The New Castle County Fire Department sent seven engine companies.
Three ambulances were also called in.
One hazmat worker suffered heat exhaustion from wearing the heavy gear and had to be taken to the local hospital.
Around 10:00 p.m., police finally got to the bottom of the possible meth lab situation.
"Through the investigation, it was revealed the individual was allowed in the home; the homeowner had mentioned that the individual was inside cleaning up the home for the homeowner," Cpl. John Weglarz of the New Castle County Police said.
Weglarz said at this point, besides household products, no other chemicals were found in the home.
While it remains unclear what household product the realtor smelled, police say it was not a meth lab.