The Chicago field office of the FCC has issued a notice of unlicensed operation to a couple in Burnsville, Minn., just south of the Twin Cities.

In the notice, the agency warned James and Sharon Norrbom that it's confirmed an unlicensed station is operating on 87.9 MHz and that the signals originate from an address on Christenson Court in that city. Commission records show no license has been issued to operate a station on that frequency in Burnsville.

The commission told the Norrboms they must shut down the station immediately or be subject to fines, equipment confiscation "and criminal sanctions including imprisonment."

They have 10 days to respond to the notice with evidence they have commission authority to operate a station.