Why do bathroom light switches usually have a cord hanging from them?

I have never seen a bathroom light switch with a cord hanging from it and I've seen a lot of bathrooms. But if i had to guess. I'd probably say to turn them off.

Electricity is conducted very easily through water. So if you let water run from your wet hands into a light switch in a bathroom there is a chance you could get a shock, even get killed. So some bathrooms have the switch on the roof with a long string to turn it on and off. So there is no chance of water getting to the switch.