Failed Experiment Wand

This wand has 2 charges. While holding it, you can use an action to expend 1 or more of its charges to cast either a green-flamed fireball or a blue lightning bolt at random from it (save DC 15). For 1 charge, you cast the 3rd-level version of the spell. You can increase the spell slot level by one for each additional charge you expend. The wand regains 1d6 + 1 expended charges daily at dawn. If you expend the wand's last charge, roll a d20. On a 1, the wand crumbles into ashes and is destroyed.