Fixing a ceiling light to a fitment with too thick wires (too powerful)

Call an electrician. Do not forget to use a registered electrician (also check registration details with scheme providers web site by name or reg number (i.e. NAPIT or other) you can check if they are actually registered and if they are qualified as full scope/inspectors also if they are current and up to date)

It's difficult to say whether the circuit has been wired in a larger diameter cable or extended using a higher rated cable, without looking at it really. In most cases people (especially DIY'ers) use whatever cable they can lay there hands on, so it may well be that there is a short section of larger cable and a connector block joint further back? The larger cable could be disconnected from the connector block and a 1.0mm or 1.5mm conductor used instead. Ideally you'd be best off hiring a Part P registered electrician to sort this out and its probably a half hour sort of job so should be relatively in-expensive.

The cable being too large is only a problem if the connections you made aren't great. For example loose connections create high resistance that in turn gives you heat. If the cables too small this is worst. Remember cable is king. Sometimes light fitting come with smaller choc/connector block connections as the largest cable it expects in a domestic installation is 1.5mm. As you are unsure of the cable size you should leave well alone. Please remember, do not attempt electrical repairs if you're unsure and always use a proper vetted electrician. A part p electrician could do this but a full scope scheme electrician would be even better. Steven Green, TMIET

Hi, I can say your last statement is 100% right "attach different size cables is dangerous", I guess you need a qualified electrician to sort it out!