The man has called at a number of homes in the Turpin Green Lane area where he has sought to gain access to homes on behalf of EDF Energy.
When quizzed by vigilant residents, he has provided an ID badge from Chorley-based home security and fire safety firm Black Box, the firm said.
But both EDF and Black Box have confirmed that the man does not work for them and are urging residents not to allow the man access to their homes.
There are also reports of the man visiting homes in Clayton-le-Woods and Buckshaw Village where he has presented the same ID.
A spokesman for Black Box Fire & Security Solutions said: "It has been brought to our attention that an individual claiming to be from EDF Energy is visiting homes locally and asking to take meter readings.
"The person in question is apparently using a Black Box ID card. Just to confirm we do not have any link to EDF or the individual concerned. Please be vigilant at all times."
An EDF spokesman added: "EDF employ two trusted partners MDS (Morrisons Data Services) and Lowri Beck to complete meter reading work on our behalf. All their meter readers would be wearing branded uniforms and carry photo identification.
"If customers are ever unsure about whether a meter reader is working on behalf of EDF, they should not let them enter their home and then contact us to confirm if it was a legitimate visit."
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