Cold callers are targeting residents in Silverdale.
Lancashire Police received several calls from concerned villagers about sales people knocking on their doors uninvited last Wednesday night.
A spokesman said: “Please think twice before allowing strangers into your house and always ask for an identification card.
“These individuals should not use heavy handed sales tactics. If you can buy the item cheaper in the shop then do so.
“Any concerns should be reported to us on 101.”