Not sure how to go about that can you advise? Thanks
I think the suggestion is to buy some single core green/yellow earth cable, then daisy chain it from the main earth at your consumer unit, to every lighting switch point and every light in your house/flat.
Another suggestion was that there might actually be cut off earth wires at the switches, which is worth checking for. The red insulated wire is covered by an outer of grey plastic, hidden between the red and the grey, you might find there is a copper wire. If there is and earth wire, the grey outer will form an oval shape, instead of a round shape which lacks an earth.
Even if there is an earth there, it is no guarantee that is connected to ground, it still needs checking out.