Answer:

Situation 1: The welding point inside the light is too high, and there is contact with the light housing leading to connection.
Test all the lights and test one light at a time, find the one that's wrong, and replace it.
Situation 2: The product with remote control module is randomly lit up due to external interference signals received.
Use wiring harness switch to turn off the power. If the user finds it troublesome, he can only upgrade the firmware and replace the self-designed remote control.