The DJ boss in Luigi’s Mansion 3 can be a bit tricky, and if you're having trouble with it, you're in the right place, because we got all the tips and methods needed to be able to beat it. The fight is divided into two phases, and during the first phase you will have to navigate between a lot of dancing ghosts. The objective during this phase is to find the ghost with the elevator button. It's not easy to do this without taking damage, but try taking as little as possible.
Once you get the ghost with the elevator button, he'll toss it to another ghost on the far left. Now try to remember the ghost he throws it to, and then to and stun that ghost to get the elevator button.
This will trigger the 2nd phase to begin, and the big DJ ghost with the red afro will take back the elevator button. She will throw records at you, and you must obviously try to dodge these. Go near her and jump in the air to get her wig to fall of. Once it is off, use the strobe light on her, then use your vacuum to deal damage to her. Now just rinse and repeat this until you defeat her, because she does not really do anything different than this. Just keep going, and she will eventually be defeated.