Firefighters have tackled a blaze at the home of Ozzy and Sharon Osbourne.
It is the second fire at the Osbournes' home in 16 months
The fire caused minor smoke damage to a hallway of the mansion in Jordans, Buckinghamshire, and a woman employee had to be treated for smoke inhalation.
None of the family was at home. A fire service spokesman said an electrical fault in a lamp was suspected.
Black Sabbath star Ozzy and X-Factor judge Sharon fled a blaze at the home last year. In 2004 Ozzy tackled a burglar who escaped with jewellery.
The Buckinghamshire Fire Service spokesman said it was alerted by an automatic fire alarm at 0725 BST on Thursday, followed by a 999 call thought to be from the family's housekeeper.
He said the blaze had been "caught in the nick of time".
"If we hadn't been alerted so quickly it could have been worse," he said.
In March 2005, a fire broke out in the Osbournes' living room while they slept.
The couple escaped to the garden, rescuing their pets as the fled.
Ozzy Osbourne tackled an intruder at his home in November 2004, before the man jumped from a first-floor window and escaped with jewellery believed to be worth about £2m.
The heavy metal star had suffered a near-fatal quad bike accident in the house's grounds in December 2003.