As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 3078 - IND-BOS - RECEIVED EICAS WARNING OF -LAV SMOKE-. RAN THE APPROPRIATE CHECK LIST AND INFORMED ATC OF THE EMERGENCY. LAVATORY APPEARED NORMAL. NO UNUSUAL SMELL WAS NOTED. MAINTENANCE REMOVED AND REPLACED THE FLIGHT ATTENDANT SMOKE DETECTOR PANEL IAW EMB 145 FIM 26-14-00-510-802-A. OPS CHECK GOOD. COULD NOT DUPLICATE PROBLEM ON GROUND.