Bind Spirit

You can cast this spell only at night. Choose a corpse of a Medium or Small humanoid within range that died violently. If the corpse has been dead for longer than one minute when the casting begins, the spell fails. If it hasn't, then your spell extracts and binds the creature's soul into your service, summoning it as a tormented spirit. The spirit rises as a poltergeist in the space of its corpse or in the nearest unoccupied space. (the GM has the creature's game statistics). 

On each of your turns, you can use a bonus action to mentally command any creature you made with this spell if the creature is within 120 feet of you (if you control multiple creatures, you can command any or all of them at the same time, issuing the same command to each one). You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures. Once given an order, the creature continues to follow it until its task is complete.

The creature is under your control for 24 hours, after which it stops obeying any command you have given it. To maintain control of the creature for another 24 hours, you must cast this spell on the creature before the current 24-hour period ends. This use of the spell reasserts your control over a creature you have bound with this spell, rather than binding a new one.

At Higher Levels. When you cast this spell using a 7th-level spell slot, you can bind or reassert control over two poltergeists. When you cast this spell using an 8th-level spell slot, you can bind or reassert control over three poltergeists or one wraith or ghost. When you cast this spell using a 9th-level spell slot, you can bind or reassert control over four poltergeists, two wraiths, or two ghosts.