What was found
AIRCRAFT WAS GNDED. ON GND PRIOR TO BOARDING, FLIGHT ATTENDANT IN AFT SECTION OF THE ACFT REPORTED BROWN FLUID & SMELL COMING FROM OVERHEAD VENT L4 DOOR, WHEN APU AIR PUT ON, SPRAYED ALL OVER FLOOR. CREW MEMBERS REQUESTED MEDICAL TREATMENT. FOUND GALLEY DRAIN & AIR SUPPLY LINES CROSSED AT AFT GALLEY ACCESS PANEL. PLACED LINES IN CORRECT POSITION. ACCOMPLISHED A SATISFACTORY LEAK & OPERATIONAL CHECK AS WELL AS TASK CARD 26L00021001, CABIN AIR QUALITY WITH NO FURTHER DEFECTS BEING NOTED.