Electrical faults are reasonably common. They include but are not limited to:

• Nuisance tripping of MCBs (miniature circuit breakers) or RCDs (residual current devices)
• Ingress of water due to excessive damp (garden or house)
• Damage to the insulation of PVC cable
• Incorrect connection in a ring final circuit
• Heat damage of cable due to power overloading of circuits