As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE FLIGHT ATTENDANT REPORTED THAT A WHITE VAPOR OR SMOKE LIKE SUBSTANCE WAS COMING FROM THE FLOOR VENTS AND COLLECTING NEAR THE FLOOR. UPON INVESTIGATING, FA REPORTED THE VAPOR FELT COOL AND HAD NO SMELL. THE CREW RETURNED TO KORD AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE AREA AND FOUND UNSECURED DUCTING NEAR ROW 8. MAINTENANCE RE-SECURED THE COOLING DUCT AND OPERATIONAL CHECKS WERE GOOD WITH NO FURTHER DEFECTS NOTED.