I came across this the other day while working in the Shankill area. Someone had wrapped the wires around each other and used Duck tape to cover them. The lights in the house stopped working. Luckily not too much overheating on the cable. This could have caused a serious fire.
Electricity is not to be tampered with and it is now illegal to complete electrical work in your own or someone elses home unless you are a registered electrician.
If you are not sure about anything in your home give me a call and I will advise you. This usually only takes a couple of minutes on the phone and their is no charge for advice on safety matters.