Electrical safety testing apparatus, including electrical safety testing apparatus having a digital or analogue display; electrical testers for residual current devices (RCD); portable electrical safety switch testers; electrical appliance testers; portable electrical testers for class 1 and class 2 appliances; portable electrical lead testers; earth leakage testers; insulation resistance testers; earth resistance testers; electrical polarity testers; electrical continuity testers; combination safety electrical testing apparatus; parts and accessories for the aforementioned goods