Two men tried to gain entry to a property in Co Armagh on the pretence of being there to check the electricity supply.
Police say they are following up on the incident which was reported in the Aghalee area.
They are treating it as suspicious behaviour and are warning people to be on their guard.
The two callers were travelling in a white van and were wearing high-visility coats.
A PSNI spokesperson said they called at an address and attempted to gain entry to the property to make checks on the electricity supply.
“On this occasion the occupier thought it suspicious and refused entry,” said the spokesperson.
“All legitimate workers from utility companies should be carrying identification and will not mind waiting whilst you call the Quickcheck service on 101.”