Let us just understand what is Electrical earthing (Grounding) and if it is really needed.
Electricity only appears when there is a potential difference between two points. For example, if we take two wires, one with a potential of 12 V, and another with a potential of 0 V, then we'll have a potential difference of 12 V. If both wires have 12 V, there will be no potential difference between them, and electric force will be zero..
Therefore, the mains electrical systems are made up of two wires, one called phase and another called neutral. The neutral wire shows a potential of zero and the phase wire is where the electric energy is transmitted. As there is a potential difference between phase and neutral, there is electric force. In mains distribution network the voltage is alternated, as the electric force of the phase wire varies along the time making a sine wave. ... (please refer to original article in the link)
http://www.hardwaresecrets.com/article/18/2