The earth grounded of LED
According to new standing and request of GB7000.1/IEC60598D:
Class Ⅰ led production must be earth grounded. Strict security measures are in force in the Class Ⅰ led production.
The Class Ⅱ led production don’t need to earth grounded.
they are double insulated and approved to international safety standards.

The earth grounded of Class Ⅱ led production can’t to earth grounded.because it belong to safe ultra low voltage (SELV)

Undesirable consequences flow from Class Ⅰ led production is not value earth grounded. This has done incalculable damage, include triggle Electrostatic Induction (caused damage to led module ), electric leakage (there is a risk of electric shock).

How to value earth grounded? Please refer to pic as follows:

With some methods, current is introduced into the earth by grounded lengths of wire