Why does the light switch pop the circuit breaker after a period of time?
I do not even know that it is the light switch that is popping your circuit breaker! It may be the switch or something else. The light switch controls a circuit. As electricity passes through that circuit it is heating up a contact or a weak place in a wire. At a certain point that hot place in a connector or in a wire allows the electricity to jump out of the circuit and not go through the light. When that happens, the circuit breaker pops.
You can turn off the circuit breaker. Then you can look at the connectors on your light switch. If one of them looks burned, You have solved the problem. You replace the light switch. Next comes the more difficult task of looking at the connectors for your lamp. If they are not easy to get to, you call an electrician.