As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK - MASTER WARNING W/ "FUSELAGE DOOR" LIGHT CAME ON CLIMBING THROUGH 20000 FEET ACCOMPANIED BY RED "EMERGENCY EXIT" ON "RIGHT FRONT" ILLUMINATED ON SYSTEM DOORS PAGE. PRESSURIZATION NORMAL. RETURNED TO DEN PER QRH. MAINTENANCE LUBRICATED FORWARD EMERGENCY EXIT DOOR PROXIMITY SENSOR PER Q400 AMM TASK 52-71-01-830-805. OPS CHECK GOOD. NO DEFECTS NOTED AT THIS TIME.