Why don’t you get electrocuted when you touch an appliance cord?
Because the wire is wrapped in materials that do not allow electricity to pass through them.
Materials can be divided into two groups - conductors and insulators.
Conductors are materials that allow electrons to flow easily, enabling an electric current. Some examples of conductors are silver, copper, water and us!
Insulators are materials that do not allow electrons to flow easily, blocking the electrical current. Some examples of insulators include rubber, plastic, wood and glass.
In the diagram you can see the conducting wires are wrapped in insulating plastic. This acts to protect us and contain the flow of electricity. Plastic coverings on light switches and power points act in the same way.