Electric power and electronic appliances are so integrated with modern life that there is a high degree of likelihood that everyone will receive one or more electric shocks in a lifetime. In many cases, only trivial power levels are involved. However, when electric shocks cause damage to humans or even result in death (defined as an electrocution), then improper control or isolation of the associated electric power must be investigated. Shocks are typically caused by faulty ground connections, inadequate insulation, or improper circuit design, often leading to an unsafe voltage difference (stray voltage) which can cause a harmful shock. Establishing the causes of shocks and their effect upon humans is key to establishing liability.