sorry should have put the sw is down stairs and it is a double 2 way sw with 6 red wires. i have had a look at putting junction box under floor but wiring is under laminate flooring
i have moved the stairs in the house but now the light switch needs moving i have bought new cable but what is the best way to joint it .
as it will be going under plaster someone told me to use block connectors with plenty of insulation tape
