It is not everyday you read about something as bizarre as this, but hey you have a look around the internet and it is amazing what you can find:
“A faulty TV digibox sparked a rescue mission from RAF Kinloss by sending out a signal identical to those transmitted by vessels in distress. The Kinloss site in Moray, which co-ordinates rescue operations across the UK, detected an “SOS” call from the Portsmouth area on 5 January.
A coastguard helicopter spent two hours searching the harbour area before the signal was traced to dry land. An RAF spokesman said the signal had been a “complete freak”. Telecoms regulator Ofcom was asked to look into the signal and confirmed the source.”
Source: BBC News