Illuminated button assemblies are provided that can be secured to a mounting surface by any of a locking member such as a snap tab, a securing member such as a nut, or a combination of both. The securing member is adapted to enclose the locking member when it is fully secured. A variety of illumination assemblies are similarly sized and shaped such that they can be interchanged within the same assembly housing. A switch and the illumination assembly are directly connected to the assembly housing without the need for a lamp holder.