As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT, TURNED OFF NOSE LIGHT AND FLASH OF LIGHT AND LOUD POP WAS HEARD COMING FROM NOSE LIGHT SWITCH. OBSERVED RT NOSE LIGHT CB POPPED. RETURNED TO GATE. FOUND NOSE LIGHT SWITCH LOOSE. TIGHTEN NOSE GEAR TAXI LIGHT SW AND OPS NORMAL REF SWP, CHAP 20. OK FOR SERVICE. FINAL CLOSED.