This is occasionally different depending on the building, but in most places, the lights will flip down. Here's how to do it:
To turn them back off:
Some light switches may be different to this, such as ones that allow you to adjust brightness. In this case, to get it right the first time, you should consult the manual that came with your light switch, or whoever installed it if you did not do this yourself.
If one of these processes don't work, try these troubleshooting steps: