Here are some safety tips from Energy Safety for buying and using Christmas lights.

Don't buy or use Christmas lights (or other electronic goods) that:

• Do not have the normal plug you would use at home.
• Are supplied with a travel adaptor to fit the socket outlet.
• Have a cord that extends up (rather than down) from the plug or a plug with no covering insulation extending half way up two it the plug pins.

When using lights:

• Connect your lights to a Residual Current Device (RCD) or an isolating transformer.
• The RCD will turn the power off when things go wrong, reducing the risk of a fatal electric shock. If you don't own a RCD already, you can buy one from any hardware or electronic store.
• Check all lights – both old and new – for broken or cracked sockets, frayed or bare wires, or loose connections. If you are unsure about their safety, have them checked by a licensed electrical worker.
• Replace bulbs with ones of the same voltage and wattage. The wrong bulbs could cause overheating and start a fire. Always switch off and unplug light strings before replacing bulbs.
• Turn off all Christmas lights when you go to bed or leave the house. If the lights develop a fault, they could start a fire.
• A tingling sensation is usually a warning of danger. If you get a tingle from your lights or something touching them (e.g. Christmas decorations on the tree (inside), the house down pipe (outside)), turn the lights off immediately and get them checked by a licensed electrical worker.

Using Christmas Lights Outside

If you are using Christmas lights outside follow the above advice and also:

• Check labels to make sure that they are suitable for outside use, and read all instructions carefully before installing your lights.
• Clean the outside of your house before installing the lights. Spider webs, leaves and any other debris are a potential fire hazard.
• Fasten outdoor lights securely to trees, house walls or other firm supports to protect the lights from wind damage. Use specially insulated clips to hold them in place and mount them out of reach.