Abstract: A cover plate for ceiling or wall mounted electrical devices which follows the contour of the surface of the ceiling or wall about such devices. A mounting plate which can be mounted to a suitable box in the ceiling or wall has two sets of tongues to engage locking members on the cover plate. The locking members are flexible tabs which establish notches therebetween to receive the tongues of the cover plate and thus fix the cover plate to the mounting plate. The two detent posts with their associated tongues are independently applied so that the cover plate can more nearly match the contour of the ceiling or wall.