This LED bulb simulates a flame to turn any light fixture into a gaslight fixture

The SIXDEFLY LED bulb screws into any E26 fixture (this is the normal size used in most US fixtures), and it uses 4W of electricity to produce 300 lumens of 1900-2200K light.  The bulb has three modes:  standard, flame, and breathing.  Apparently, you switch the light switch on/off to switch between the three modes.  For best results, you should use the bulb in a lamp with a frosted shade, a lantern, or a salt lamp.  The SIXDEFLY Flame bulbs are available from Amazon; they are $18.50 (with free Prime shipping) for one or $56.99 for a set of three.