Drinking 70% moonshine???

Hey guys not much of drinker, I have a friend who has friend who makes his own alcohol and made 70% (I have no clue but he said it was from grain), just wanting to know how careful do I have to be? is it as simple as putting like 5ml and mixing with a soft drink, I have already had a shot with water in it and my god is it smoother then any alcoholic shot I have ever drank. It seems to good to be true.