You can see the LED replacement light in my Featherweight above on the right. The photo on the left is with the traditional light bulb I just retired. (Yes it is ON. Hard to tell, isn't it?)
This LED replacement light is powered by the sewing machine and plugs into the same place where your current dull bulb lives, so no wires. A screw keeps it in place. This LED light is appropriate for both 221 and 222 models.