"Internal electrification works" typically refer to the electrical installation or wiring within a building or structure. This includes all the electrical components such as wiring, switches, sockets, distribution boards, lighting fixtures, and any other electrical equipment needed to provide power within the building.
These works are essential for ensuring that a building has a safe and reliable electrical supply to power appliances, lighting, heating, and other electrical devices. Internal electrification works are usually carried out by qualified electricians following local building codes and safety standards to ensure the safety of the occupants and the proper functioning of the electrical system.