1. Your safety switch keeps tripping
It's common for a safety switch to occasionally trip; after all, that's what it's there for - to shut off the power if your system is overloaded. However, if your safety switch trips a few times a month or more, it's a sign that there may be a problem with your home's wiring.
2. Flickering, buzzing or dimming lights
Another symptom of outdated or damaged wiring is flickering, buzzing or dimming lights. Perfectly safe wiring can occasionally do this, but if your lights are constantly dimming or flickering, again this may be a wiring problem.
3. Power points which are hot
Many electrical appliances generate heat during operation. However, a power outlet should never get hot.
4. Burning or acrid smells
If you can smell any burning, smoky or odd odours it could be coming from your wiring. Burning smells often mean that there might already be some fire damage.
If you notice any of these signs, then call your local electrician. This is one job you can't investigate yourself and must be left to a registered professional.