Sparker (trap idea)
Here's one for you DM's that want a trap the will shock your players (I'm Not Sorry For The Pun) The Player's are trying to take a short cut in a dungeon when the area they were shot cutting though has this weird black tube that flows around the room. If the players go within 5ft of this tube they will have to do a dex save or take 1d4+2 damage from getting shocked from this tube. If they have any metal on them, increase the 1d4 +2 to 1d8+4 damage. If at any point they touch the tube make them roll a con save & on a success they will take 1d8+2 damage (On a fail times that damage time two, if they have any metal on them time that damage by two as well [making it so in some situation they can take x4 damadge.).