A panel of rectangular shape comprising a plurality of electric devices spread over the panel, a control unit including a microprocessor and a power supply, drivers for driving the electric devices based on control information received from the control unit and electric wiring connecting the control unit, the drivers and the electric devices, the shape of the panel being adaptable by removing one or more parts of the panel by cutting, sawing, milling, drilling or other suitable methods, wherein the control unit and the drivers are positioned closer to a first side of the panel than to a second side opposite the first side. The drivers and electric devices are partitioned into groups that each comprises one driver that exclusively drives the electric devices in that group.