Electrical wiring is designed to be as safe as possible. The average user will never see long lengths of bare copper wire; instead most wire used in residential electrical systems and electronics is insulated to protect against electrocution, crossed wires and short circuits.
This safety feature does not mean that electrical wiring is safe to handle or work on without precautions. Never attempt to dismantle, repair or modify an electrical appliance or machine without completely disconnecting it from a wall socket or power source. Even when the unit is unplugged, there is still a danger of electrocution if you don't know what you're doing. Many electric devices contain something called a capacitor which retains an electric charge even when the unit is completely unplugged. It is important to treat all electrical wiring, appliances and other items which come in contact with live current with respect and the understanding that even when turned off and unplugged, there is still potential for electrocution.