There have been less than 1500 players who occasionally get above 90% accuracy so it's hard to tell if they're cheating. The best way to tell is by going through their profile, if they've won every game that means they're cheating or they're a chess master in disguise.
Is a 97% accuracy cheating?

If you suspect someone of cheating, report them.
https://support.chess.com/article/209-how-do-i-report-someone
If you check through your own games carefully, you may find games where you scored about 97% accuracy.
https://support.chess.com/article/648-what-do-i-need-to-know-about-fair-play-on-chess-com
Cheating discussion is not allowed in the forums.
If you will like to discuss about cheating, you can join this club https://www.chess.com/club/cheating-forum
Just lost a game to an 1800 who played at a 97% accuracy, according to chess.com’s game review. The game was 18 moves long, and I played at an 86% accuracy. Was my opponent cheating?