Householders are being told to think very carefully if they are confronted with a dubious new sales technique - doorstep traders selling "We don't buy from the doorstep" signs.
The warning from trading standards officers in Warwickshire comes after they received a complaint from one woman who bought a sign for £1.
She was told her current sign, which had been provided for free by Warwickshire Police to deter hawkers and traders, was no longer suitable and she should buy a new one.
Noel Hunter, director of Warwickshire Trading Standards, said: "Not only is this doorstep seller ignoring signs Warwickshire residents are already displaying, he is claiming their signs are no good.
"We have looked at this sign and it contains none of the emergency contact information or good advice that our own and the police's free signs both contain, yet it costs £1.
"We are concerned that some vulnerable consumers may be misled and would therefore ask that anyone who has any information about the whereabouts of this trader to contact our service."
Residents wanting a free doorstep sticker can contact Warwickshire Trading Standards Doorstep Sticker order line on 0800 413 332.