Diagnosis
The light control relay on the logic board is stuck closed. This is a common board failure on model 54930.
How to Fix It
The logic board needs replacement. Unplug the opener. Remove the light lens and bulb. Disconnect the wiring harness from the board. Unscrew the old board. Install the new logic board, part #41A4274. Reconnect all wires precisely.
If That Didn't Work
Check light button on the wall control. It can stick in the on position. Clean the button contacts or replace the wall station.
Heads Up
The constant light draws power and generates heat. This can shorten the bulb life and is a symptom of impending board failure. Replace the board soon.