The earth wires have been omitted for clarity and would need to generally be connected whatsoever switches and ceiling roses. The wires would even be covered with the protecting outer sheath (cable). When the appliance is effective as expected, the wiring is profitable. However, if you can find any concerns https://dallasssoje.ampblogs.com/5-simple-statements-about-smart-power-points-and-switches-explained-71498121