Do you have resistors wired in?
You can use the LED on board at pin 13 without resistors, others need resistors wired along with the lamp.
If you don't have any resistors with your switch you're doing it wrong. You can use a switch without resistors by wiring it between a digital pin and ground then turning on the internal pullup resistors. Then HIGH is off and LOW is on.
Without resistors you could be damaging your Arduino.