HUDDERSFIELD people preparing for Hallowe'en "trick or treaters" at their doors are being urged to guard against less welcome callers.
British Gas is issuing advice to householders after a survey on bogus callers carried out by the company and the Help the Aged charity.
It revealed that the average age of people targeted by bogus callers was 78.
In Yorkshire alone during 2002, almost 29,000 elderly people fell victim to door-to-door conmen.
Thieves will often pose as council, gas, electricity and water workers or window cleaners.
They can work alone or in small groups.
Once in the house, they distract the homeowner and pocket valuables - even life savings, which some elderly people prefer to keep in the house rather than a bank.
To guard against con artists, British Gas urge elderly people not to open the door to strangers without checking through a viewer.
People should also put a chain lock on before opening the door and should ask to see the caller's ID.
If you are unsure whether the caller is genuine, contact his or her employer to check. Details should be on the ID.
Genuine callers should be happy to wait outside while you do this.
If you are unhappy dealing with the person alone, ask them to come back later, when a friend or neighbour can be with you.
Callers should never be left alone in the house.
British Gas area manager Dennis Jarvis said: "The company is very concerned about bogus caller crime, so we're reminding people about the dangers of inviting strangers into their homes."
British Gas was one of the first firms to sign up to a national ``cold calling" scheme set up by Trading Standards last year to help combat distraction burglary.
The scheme states how sales staff should introduce themselves and the company when calling door-to-door.
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