The Delaware Department of State said it has received multiple reports that a fake card is being used to pass off wearing a mask in public places.
Several business owners have told DOS about the card, which claims to be from the "Freedom to Breathe Agency," which is not a government agency.
Masks are required or strongly recommended at many Delaware businesses, although there are some legitimate exemptions for medical reasons.
"Wearing a face mask posses a mental and/or physical risk to me," the card reads. "Under the Americans with Disability Act (ADA), I am not required to disclose my condition to you."
"Denying access to your business/organization will be also reported to FTBA for further actions," the bottom of the card says.
The federal Department of Justice also issued an alert about the card, saying it was an unsanctioned use of the department's seal.
"These postings were not issued by the Department and are not endorsed by the Department," the DOJ said. "The Department urges the public not to rely on the information contained in these postings and to visit ADA.gov for ADA information issued by the Department."
Information from NBC10 was used in this report