An assembly of a lighting unit and a receptacle unit includes at least one receptacle unit and at least one lighting unit. The receptacle unit has an outer housing provided with at least one first connection portion and at least one second connection portion electrically connected to the first connection portion in the outer housing. The lighting unit is electrically connected to one of the first and second connection portions of the receptacle unit, so that the lighting unit and the receptacle unit can be independently rotated in relation to each other along a connection axis thereof.