What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DURING DESCENT INTO DFW DUE TO A FLIGHT ATTENDANT CALLED REPORTING SMELL OF ELECTRICAL SMOKE/BURNING NEAR ROW 21. AFTER RUNNING QRC, SMELL DISSIPATED. THE AIRCRAFT LANDED SAFELY AT DFW WITHOUT FURTHER INCIDENT. MAINTENANCE ACCOMPLISHED THE SMOKE / ODOR / FUMES TROUBLESHOOTING TASK CARD 26L00021001 WITH NO FAULTS / ODORS NOTED. NO DEFECTIVE COMPONENT WAS IDENTIFIED BY MAINTENANCE TO BE THE CAUSE OF THE ODOR.