What was found
COCKPIT FIRE SWITCH: L ENG FIRE SWITCH- LIGHT BEHIND SWITCH WOULD ILLUMINATE INTERMITTENTLY WHILE IN CRUISE FLIGHT. ALL ENGINE INDICATIONS SHOWING NORMAL, NOT ACCOMPANIED BY ANY AURAL WARNING. UPON 1ST BATT POWER UP. PERFORMED ENG FIRE TEST & BOTH ENG SWITCHES REMAINED ON & ILLUMINATED. TAPPED & SHOOK GLARESHIELD, NO DEFECTS NOTED. ACCESSED SWITCH, ALL WIRES SECURE IN SOCKET. REMOVED SWITCH & FOUND SOCKET TO SWITCH BODY CONNECTION LOOSE. REMOVED SWITCH & FOUND THE BODY COULD USE AN ADDITIONAL SQUEEZING AS TO BRING CONNECTION TO A TIGHTER FIT. SECURED SWITCH BODY CAPSULE ONTO ELECTRICAL PLUG & PERFORMED OPS CHECKS. NO DEFECTS NOTED. PER MCC, WORKED IAW AMM 26-20-00 / 31-10-50.