15v Japan fancy lamps

15v Japan bulbs: I do not have wiring for these but each bulb is marked 15v Japan, and the outer box is marked No.2 SMALL FANCY LAMPS, made in occupied Japan.  This dates the bulbs to the period 1945-1952.  In addition to the box of 25 bulbs I also have one single pink/white lantern also marked 15v Japan.