The 87-year-old woman was at her home in Prestonpans at around 6pm on Monday when a man called at her door.
The man asked her to hand over a three-figure sum of cash for work he claimed had been previously carried out on the property. However, the woman refused and the suspect left the area.
Officers are currently conducting local enquiries to trace this individual and anyone who can assist with their investigation is asked to come forward.
He is described as white, average height and wearing a black beanie hat.
Inspector Andrew Harborow said: “Fortunately the homeowner was not taken in by the suspect’s rouse and refused to hand over any money.
“Nevertheless we are keen to locate the suspect and anyone who remembers seeing anything suspicious in the area on Monday evening is asked to contact police immediately.
“I would continue to urge the public never to allow unsolicited callers to carry out work on your home and only ever use trusted and reliable tradesman.
“In addition, if anyone claims to have undertaken maintenance or gardening services on your behalf, do not hand over any payment. Consult people you trust and if you have any concerns then report the matter to police.”
Anyone with information can contact Police Scotland on 101 or alternatively, the charity Crimestoppers on 0800 555 111.