**READ FIRST** Please, only do this when you're positive that someone's hacking. Wether or not they have yet killed, keep in mind that the cheaters are capable to do things in a way they're not meant to be. Depending on the situation (and how disruptive the hacker can be), you're free to call them out with the help of a group member, as already mentioned in the title.
If playing in group: Guide your partners right away to avoid the hacker and consequently report your body if they have killed you. "My friend and I are on Discord, [color] has killed him. He's a hacker, please kick."
If playing solo: Just pick a random color from the ghosts and write the same thing from above.
Maybe this is common knowledge, but given the weight of this statement, people will actually believe you. Despite the fact that Innersloth is apparently dealing with hackers, they're still an annoyance. Therefore, deal cheaters with cheats; possibly, the very and only fair use of this strat.