Hello, yes. PWM is used to change the brightness or speed of a motor (for example). Are you talking about controlling the brightness of an AC lamp?
I’ve never used this module before (I’ve ordered mine 3 weeks ago), but II think it does exactly what you’re looking for: http://s.click.aliexpress.com/e/n6PClGU
This module should allow you to control an AC light with PWM.