Each room has its own electricity cupboard. For the electricity to work perfectly, all switches need to be up at all times. If any of the switches are down you just need to switch them back up and your electricity should work again.
In case they keep switching down, take a look around your room and unplug any appliance which might cause a short circuit.
Our video tutorial here clearly shows how to handle this issue.
In case you have done as instructed but your electricity still does not work, please consult the caretaker of your building as he will gladly help you! You can submit a repair request to us and our team on site can have a closer look at it.