No. Under no circumstances should you ever borrow a neutral this is very dangerous.
The two live wires that's neutral and line must both come from the same protective device. This has caused many problems in last 2 years where RCD's have been fitted and have highlighted borrowed neutral problems.
The neutral likely will need to come from the ceiling rose.
Also separating the line and neutral will also cause interference. Years ago it was common to use just a pair of wires between switches on two way switching. This has now been stopped and always three core and earth is used now not only because of borrowed neutral problems but to reduce mains hum on radios and TV's etc.
Any AC line must be correctly terminated if power is not going to leak. With 50Hz not really too much of a problem but if you talk to anyone using a CB they refer to SWR really it's vSWR but that does not really matter. But principle is the same and if the return does not follow same path as feed then you will get mains hum on all sorts including telephone, and internet connection and it could even cause the broad band connection to fail.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!