An arrangement I once saw consisted of a local resident running a chain of domestic extension leads through an upstairs window of their house, up a front garden tree, across the public highway, to a tree on the village green, down to the grass, then running along the grass to power various lights for an evening event. The plugs and sockets were made IP68 by the cunning technique of wrapping them in carrier bags. (I am not endorsing this approach.)

The plugs and sockets were made IP68 by the cunning technique of wrapping them in carrier bags. 
well, at least it meets the letter of the plug and socket regulations. The use of waterproof connectors to EN 60309  probably would have been safer but apparently in contravention of the rules.  But joking aside, we've surely all seen this sort of thing haven't we, and while it looks pretty dire (*), in practice there simply are not enough accidents to  make it worth getting too  steamed up about..
Mike.

(*) in another role I have one talks of 'power of opportunity' when extracting electrons from somewhere not originally intended, and that often looks even more dire...

The plugs and sockets were made IP68 by the cunning technique of wrapping them in carrier bags. 
well, at least it meets the letter of the plug and socket regulations. The use of waterproof connectors to EN 60309  probably would have been safer but apparently in contravention of the rules.  But joking aside, we've surely all seen this sort of thing haven't we, and while it looks pretty dire (*), in practice there simply are not enough accidents to  make it worth getting too  steamed up about..
Mike.

(*) in another role I have one talks of 'power of opportunity' when extracting electrons from somewhere not originally intended, and that often looks even more dire...