For magic users. This appears as a Wand of Magic Missiles, allowing the user to cast one Magic Missile spell per charge, up to a maximum of seven per day.
When used in actual combat, though, the wand still fires missiles normally, but offers up a terrible surprise: upon activation, the user will switch places with the target creature, with both teleporting across from each other. What's worse, the Magic Missiles continue to strike at the target creature, only now, the wand user is the target creature! (If the Magic Missiles were aimed at more than one creature, the want user will switch places with the first.)
The victim will take normal Magic Missile damage, and be in the same spot where the creature was just located, even if that's in the midst of enemies, while the creature is (or may now be) right in the middle of the party, totally unharmed by any Magic Missile attacks from the wand.
When this curse activates, the wand behaves as described, using up however many charges the user had intended (with the user being hit with however many Magic Missiles), then it crumbles away to dust.