I live in a modern house that was built 7 years ago and we had a loft extension built a couple of years ago. We are in the process of re-decorating the loft and decided that chrome plated flat sockets and light switches would complement the modern look we were trying to achieve.
The fittings were ordered and received but I noticed that the light switches have earth connectors and a label saying "This metal plate must be earthed using the terminal marked earth".
On closer examination of my light switches, they don't appear to have earth cables, just a live and switched live wire! The ceiling roses do have earth connections but this earth isn't taken to the switches. I know from experience that this isn't unusual and is the way that the last three new houses I have lived in were wired.
Is it necessary for me to run an earth cable from the ceiling rose to the light switch in order to fit these new metal boxes?
Could you also help me with the definition of a lug. Another label on the switch says "If a 4 lug mounting box is used, the top & bottom lugs must be bent fully back". Is the lug the thing in the mounting bot that the screws screw into? I'm fairly sure it is but I'm not sure why you would ever get 4 in a mounting box. Because the light switches are fitted to plaster board walls in the loft, plastic mounting boxes have been used which have the adjustable fixings i.e. they pull tight onto the plaster board when the switch fitting is screwed on.
Thanks in advance for guidance on earthing the metal switches.