If you have only twin cable with no earth, you really should be rewiring you lighting circuits.
Has the box in the wall that you have not got nylon blocks fo the plate screws to screw into?
Were you planning on installing a metal faced switch?
Have you checked your main equipotential bonding (there should be a 10mm2 green and yellow cable going to the water and gas service and should be connected to these services within 600mm of the meter/stoptap/or where the enter the building) ?
Do you have any RCD protection?
Has the box in the wall that you have not got nylon blocks fo the plate screws to screw into?
Were you planning on installing a metal faced switch?
Have you checked your main equipotential bonding (there should be a 10mm2 green and yellow cable going to the water and gas service and should be connected to these services within 600mm of the meter/stoptap/or where the enter the building) ?
Do you have any RCD protection?
