Arc Trap

You place a trap up to 15 ft away (combat range) that stores arc lightning.  When the trap is triggered, the enemy must succeed in a Dexterity Saving Throw or take 1d8 (+ Wisdom Modifier) damage.  They take half on success.  Either way, a stack of static is applied.

At higher levels, the enemy takes Xd8 (+ Wisdom Modifier) damage, where X = the level of spell slot used to place the trap.  At 3rd and 4th level of spell slot, the enemy receives two stacks of static.