A locating device for locating a body such as an electrical box behind a wall or ceiling. The device includes a first member positionable in the body and a second member that can be positioned on the outer surface of the wall or ceiling. A magnet positioned in the first member cooperates with a magnet positioned in the second member to maintain the second member in an aligned position with respect to the electrical box. Two magnets can be used to enhance the alignment of the second member with the electrical box. A circular first member can be used for locating circular boxes or lights. A second member having an arm can be used with a circular first member. The second member can include a plurality of apertures, each aperture sized to correspond to a specific size light or electrical box.