As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A STRONG BURNING ODOR WAS OBSERVED THROUGHOUT THE CABIN AFTER TAKEOFF FROM IAH. THE AIRCRAFT WAS RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE OVERHEAD ELECTRONIC UNIT (OEU) FOR WORK LIGHTS AT L-3 AND R-3 DOOR AT FAULT. THE OEU WAS REMOVED AND REPLACED IAW MM 23-33-02-000-803. OPERATIONAL CHECKS WERE GOOD.