Xcel Energy is warning residents in the Denver metro area about a scam involving men posing as company employees.

More than a dozen times this week, two men claiming to be with the power company have asked to enter a customer’s home to check voltage on the outlet.

The two men were denied entry in the known cases. But there was an incident in which one of the men stated “either we come in or we press charges.”

Both men were described as wearing light grey shirts and dark grey pants, but with no name tags. They appear calm until they are denied entry, at which point they become more aggressive.

All Xcel Energy says all employees and most contractors who perform work for the company carry company ID cards.

Excel says customers should always ask to see a company ID if someone on customer property claims to be working for Xcel Energy.

If the person cannot show an ID, customers should ask him or her to leave, and return only with proper identification.

If there are questions about someone claiming to work for Xcel Energy, call 1-800-895-4999.