Standard house wiring uses black for hot/live, white for neutral, green of bare for ground.
Don't go by the colors unless you are absolutely certain. If this is in an old cabinet, the operator might not have had any idea what he was doing. Use a multimeter.
Measure the voltage across 'L' and ground. If it reads about 120volts, then 'L' is hot. If it reads about zero, then 'L' is neutral.
The switched wire is certainly the hot/live wire.