As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN EMER LTS CAME ON BY ITSELF 40 MIN OUT WENT OFF 10MIN LATER . PERFORMED OPERATIONAL CHECK OF EMERGENCY LIGHTS FLT DECK SWITCH REF MM TASK 33-51-00-720-801. ALL ADVISORY EICAS MSGS PRESENT AS REQUIRED. COULD NOT DUPLICATE AT THIS TIME. OK TO CONTINUE