As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW RECIEVED A LAV FIRE WARNING. CREW RAN QRH AND IAW THE F/A, THERE WAS NO VISIBLE FIRE BUT THERE WAS SMOKE. CREW DECLARED AN EMERGENCY AND ELECTED TO RETURN TO DEPARTURE, WHERE THEY LANDED WITHOUT INCIDENT. MAINTENANCE PERFORMED COLD SECTION BORO AND OPS CHECKED BLEED SYS IAW AMM WITH NO OIL LEAKS OR BURNING ODORS PRESENT. ACFT OPS CHECKED GOOD AND IS GOOD FOR SERVICE.