Hereford Library was evacuated on Nov. 2 after customers and staff smelled a burning odor and called 911. The culprit turned out to be a faulty light.
Firefighters from Hereford and Parkton took the call at 3:34 p.m. and searched the library, an outside equipment room and the roof.
Firefighters found that a fluorescent light ballast overheated, causing the smell, said Lt. Ken Wirtz Jr., with Parkton fire station 60. A ballast is a device that a holds a fluorescent light. It regulates current the light receives.
The light, which firefighters dismantled, was above a section of books in the fiction section.
Wirtz said a thermal imager was used to find the source of the problem.
Firefighters left at 4:10 p.m. and the library re-opened.