How many lights can a light switch control?

A light switch is to be used within its ampere rating. You would have to calculate how many amps each light needs then divide that number into the ampere rating of the switch. Round down, do not exceed the whole number.

Example: a 75W light bulb would need 0.625 amps at 120V (I=P/E)

a 15A switch could have 24 75W light bulbs (15/0.625)