Abstract: An improved electrical lock box having particular application for mounting cable television distribution units. The lock box comprises an open faced housing having opposing side flanges which extend inwardly, and a cover having an inwardly extending top end flange. The cover also includes horizontally aligned slots in its top end which slidably and pivotally engage the housing side flanges to position the cover in overlying relation with respect to the open housing face. Safety locking indentations are provided in the housing side flanges which automatically engage the cover slots when the cover is moved downward, preventing inadvertent movement and dislodgement of the cover. The cover slots and indentations are dimensioned such the cover disengages the indentations when the cover pivoted about the horizontal access defined by the slots.