Verses with the word mischievous in the Old Testament (5 verses):

Psalms 21:11
For they intended evil against thee: they imagined a mischievous device, which they are not able to perform.

Psalms 38:12
They also that seek after my life lay snares for me: and they that seek my hurt speak mischievous things, and imagine deceits all the day long.

Proverbs 24:8
He that deviseth to do evil shall be called a mischievous person.

Ecclesiastes 10:13
The beginning of the words of his mouth is foolishness: and the end of his talk is mischievous madness.

Micah 7:3
That they may do evil with both hands earnestly, the prince asketh, and the judge asketh for a reward; and the great man, he uttereth his mischievous desire: so they wrap it up.