After the theft of tools or materials (copper wire is very theft attractive) the most likely claim an Electrician will be involved in will be a fire claim.
Fire claims are more common for electrical contractors who do work in existing buildings, especially older ones. This is because they are more likely to be connecting new components to existing, older wiring, fuse boxes and components. This increases the chance that the older installations will overheat and cause a fire.
This is why it is so important for Electricians to have good Public Liability Insurance Cover. If the house burns down, you can be content in knowing that your public liability insurer will look after the settlement and payment of the resulting claim.
This is the case, even if it is determined that the old wiring caused the fire. The fact that you have been working on a premises means it is likely you will be brought in on the claim. Your public liability insurer will defend you in respect of this claim and ultimately pay these defence costs.