housing 14 is cut away to leave two legs 44 as shown in fig4 a printed circuit board containing the drive circuitry 16 fits between the 34 legs 34 44 of the inner housing 14 the flexible circuit 33 that is connected to the contact pads 32 are led through a channel not shown cut in the inner housing 14 and connected to the drive circuitry 16 connection is accomplished by inserting contact pins that are soldered to the flexible circuit 33 into sockets provided on drive circuitry 16 the ends of the legs 44 are turned inward to form feet 46 for mounting the spring switch 20 space between the drive circuitry 16 and the spring switch 20 is provided for mounting a battery 18 the battery 18 may be of a type having and integral lead for connection to the drive circuitry 16 the spring switch 20 is preferably formed from spring temper carbon steel and plated with a suitable material to prevent corrosion and provide good electrical conductivity the switch 20 is formed from a thin strip of material and the ends are turned up to form a barb 48 that fit through the slots 50 in the feet 46 of the inner housing 14 the barbs 48 are bent over after being inserted in the.