Using earth as a neutral wire for domestic purpose is not safe even not legally recommended.let me explain why?
1.First is SAFETY:- When we talk about safety of human beings and domestic appliances like small machines then during abnormal conditions earth neutral wire carry current which may damage. During abnormal conditions earth wire provides low resistance path to leakage currents and if a person touches the appliance, he remains safe as his body resistance is more than that earth wire and no current flows through his body.