(I can just imagine the 4 way adapters plugged into 4 way adapeters at the end of an extension lead from the shed powering all the OTT decorations including the inflatable santa and the eating Rudolf!)
Yh i went to a job last year (Fire Service) where they had 2 4 way adapters plugged in together all used up, this included fairy lights around the bedroom sadly to say the bedroom was totally gutted and luckily no one was at home.
to be fair though if its done professionally its safe if the correct rated mcbs per light set is used, for example i have coloured par38s in the garden on a time clock, bit each light is wrired to a consumer unit, where each lamp is on its own 6 amp mcb so it can only take out 1 light if that light develops a fault, will take some pics later in the week, and place them here