However it goes, for electricity to do any damage it has to have a circuit, this is why birds perch on the HT lines and linesmen in fact can work on live lines in safety, the danger comes when they touch one of the other lines or an earth. I suppose in theory you could swim about quite happily and not get a shock untill you touched the side of the pool to get out. Also everything, even the best conductors known have some electrical "resistance". The greater the distance the greater the "resistance" and the greater the volts drop, so the futher away from the source the lower the voltage. As to the hair drier in the bath the current would go through the water and you to earth through the bath. Incidently there is an old saying that voltage burns but ampage (current ) kills. I personally know several people who recieved bad burns on 3,300v and survived while one another was killed on 550v with a higher currant