An electrical device comprising a housing for electrical circuitry, the housing defining a cavity opening to the exterior of the device. The cavity includes a first and second fixing arrangement capable of mechanically interlocking with a power connection insert to fix the power connection insert in position. The power connection insert provides a power cable or power connector that couples the electrical circuitry to an external electrical power supply for the device. The use of different power connection inserts allows a wide range of connector types to be provided using a single design of the housing.