Incredibly attractive and erotic women. Capable of turning somebody on as a light switch would.
Jon: Emily was looking bad today.
Alfred: Facts, she is a light switch.
A constant on and off again relationship
Cole and Jake are split up again, they have such a light switch relationship
Means to say duh to someone when they finally got something correct or they understood something.
Quincy: I heard you and your girl broke up
Jamal: Bruh yea I cut that hoe off like a light switch you just now knowing now that’s light switch