ESB Networks is asking residents in Tralee to remain vigilant and always ask for identification.
Last Friday, an elderly woman living in Connolly Park answered the door to a man claiming to be from the ESB and looking to check power wires.
The man gained entry to the house and stole a large sum of money, which the woman was saving for Christmas.
ESB Networks says it is aware of the case adding that their staff and contractors are required to carry and display identification.
If a person is in doubt the local Gardai should be contacted.