Abstract: A modular electrical fitting suitable for the instrument panel of a motor boat, has a plastic housing 8, 9, 10, having a rectangular foot print, with each side having a shaped upper edge, and a connection cavity 11 positioned in the uppermost portion of each side edge, so that the modular unit 8, 9, 10 can be connected together by means of a resilient joining device 13, which can be pushed in place to physically connect two of the modular units together as shown between units 8 and 9. This enables the modular units to be held together from above, whilst the underside of the units can be connected together by brass bus bars or the like to provide a secure electrical connection between adjacent units, so that the modular units can be connected together box physically and electrically. Each of these modular units 8, 9, 10, etc can be provided with a switch, fuse, or other electrical component, so that the modular units can be connected together to form an entire switchboard or instrument panel.