An adjustable mounting assembly for mounting an electrical module relative to a supporting surface, comprising: mounting means adapted for embedded anchorage relative to the supporting surface; a holder having an aperture for receiving and holding the electrical module, the holder being adapted for moveable engagement with the mounting means to facilitate adjustment of a position of the electrical module relative to the supporting surface; and fastening means for fastening the holder to the mounting means, the fastening means being accessible for unfastening and refastening via the aperture to facilitate re-adjustment of the position of the electrical module relative to the supporting surface, wherein the mounting means includes an annularly-shaped substantially flat portion and an opening, adapted to receive the holder, wherein the fastening means includes an annular rim, one or more screws and one or more washers, the rim including one or more corresponding threaded screw holes to engage with the one or more screws, the rim being secured or otherwise attached to the substantially flat portion of the mounting means, and the rim defining an opening no smaller than the opening of the mounting means so as not to obstruct movement of the holder relative to the mounting means, wherein to facilitate the moveable engagement between the holder and the mounting means, the holder includes an outer engaging surface shaped to correspond with a corresponding inner engaging surface of the mounting means, wherein the pair of corresponding engaging surfaces and are similar in cross-section in size and shape to allow the holder and the mounting means to slide over each other, wherein the holder includes one or more tracks (14a and 14b) for engaging the fastening means; and wherein to fasten the holder to the mounting means once they are in a desired relative position, the one or more washers and the rim are arrangeable to sandwich and press against the one or more tracks (14a and 14b) of the holder for securement via the one or more screws. mounting means adapted for embedded anchorage relative to the supporting surface; a holder having an aperture for receiving and holding the electrical module, the holder being adapted for moveable engagement with the mounting means to facilitate adjustment of a position of the electrical module relative to the supporting surface; and fastening means for fastening the holder to the mounting means, the fastening means being accessible for unfastening and refastening via the aperture to facilitate re-adjustment of the position of the electrical module relative to the supporting surface, wherein the mounting means includes an annularly-shaped substantially flat portion and an opening, adapted to receive the holder, wherein the fastening means includes an annular rim, one or more screws and one or more washers, the rim including one or more corresponding threaded screw holes to engage with the one or more screws, the rim being secured or otherwise attached to the substantially flat portion of the mounting means, and the rim defining an opening no smaller than the opening of the mounting means so as not to obstruct movement of the holder relative to the mounting means, wherein to facilitate the moveable engagement between the holder and the mounting means, the holder includes an outer engaging surface shaped to correspond with a corresponding inner engaging surface of the mounting means, wherein the pair of corresponding engaging surfaces and are similar in cross-section in size and shape to allow the holder and the mounting means to slide over each other, wherein the holder includes one or more tracks (14a and 14b) for engaging the fastening means; and wherein to fasten the holder to the mounting means once they are in a desired relative position, the one or more washers and the rim are arrangeable to sandwich and press against the one or more tracks (14a and 14b) of the holder for securement via the one or more screws.