Fire crews from Shepton Mallet and Castle Cary were called out to the Greencore factory in Evercreech on Friday morning after a light fitting caught fire.
The alarm was raised just after 5.30am at the factory, which was previously known as Uniq.
Firemen isolated services at the site and used a cherry picker to reach the high level sodium light and remove the fitting.
The cause of the fire is thought to be accidental.
There was fire damage to the light fitting and smoke damage to the ceiling nearby.