Always Disconnect the Power before beginning work! Failure to follow this rule can result in death or injury.
Breaker and fuse panels remain hot even if the main breaker is turned off or the main fuse is removed. Main panels should only be worked on by qualified persons.
Incorrectly performed electrical work can result in fire, damage to property, and injury or death to people. Furthermore, in some jurisdictions it may be against the law for anyone other than a licensed electrician to perform electrical work, and work which is performed by unqualified people or which has not been inspected and approved may cause your homeowners insurance policy to be void.