Electricity can be a Killer

Power to the elbow makes light work of many DIY jobs but electricity can be a killer unless we use it safely and sensibly.
Keep water away from anything electric. Don't even wash walls without turning off the power at the mains switch.
Never be tempted to use a socket or plug or equipment which could still have water in or on it - allowing it to dry could mean the difference between life and death.
Read manufacturer's instructions on extension cables - they could overheat if left coiled. Check an extension is appropriate for the appliance it is connected to.
RCDs
RCDs (Residual Current Devices) can respond to changes in the flow of electric current. For example, when a flex or cable is cut or an electric tool malfunctions, and direct contact is made with a mains supply conductor and earth, the RCD automatically disconnecting the power supply to the equipment to reduce the risk of you being electrocuted.

RCDs are available in several forms:
... as portable adaptors
... incorporated in socket outlets
... as separate stand alone units for fixed wiring installations offering whole house protection
... as modular units for use in household consumer units
However, although RCDs are a vital safety aid, they can't guarantee 100% protection. Even with them in your home, isn't it better to make a long term investment in good safety practice by looking after appliances such as hedge cutters, hedge trimmers, chainsaws, drills and sanders.
Do not work with electricity in damp or wet conditions. If you MUST, always use an RCD. Always place the cable of a hedge trimmer or mower over your shoulder and keep it behind you at all times.