In Germany, work on the electrical installation of a home may be done only by the grid operator or by an installation company entered in a grid operator’s register. Maintenance is the exception. A consumer guide on t-online explains what this means at home. Lamps may be hung up and taken down, but connecting them should be left to professionals. The electrical trades association says the same holds for work that seems simple, such as replacing a socket. A person who does it anyway must expect that the insurance will not pay after damage.