The only thing authentic about shab bara'at (15th of Sha'ban) is that the prophet (saw) has advised us to spend the night in worship and the day in fasting 1. He went to the graveyard of Madinah on this night and prayed for the dead 2. Anything beyong that is nonsense
get some coffee ready if you have to ;)
1. Ibn Majah, Bayhaqi (narrated by Sayyidina Ali) 2. Ibn Abu Shaybah, Tirmizi, Ibn Majah, Bayhaqi (narrated by Sayyidina Aysha)