I was looking at my list of TV shows in Plex, and saw a ton of entries for "Rules Of Engagement", which seemed odd, since I never got into that show... then I checked out a few of them and found they're actually a mish-mosh of older sitcoms like Night Court, Titus and Spin City.
Far as I know most of these are properly named - folder with the show name, subfolder with the season, and filenames with show, season, episode number, and sometimes episode title. So where is Plex getting confused??
Here's an example: Rules of Engagement S01 shows 167 titles on the thumbnail... randomly picking "E02 - The Birthday Deal" for playback, I get Night Court, Season 1, Episode 2 (full path: V:\TV\Sitcoms\Night Court\Night.Court.S01.DVDRip.DivX\Night Court - 1x02 - Santa Goes Downtown.avi)
Another: S03 containing 46 files, randomly choose "E53 - Episode 53"... the thumbnail does actually show a scene from WKRP, and amazingly... it is actually an episode of WKRP (V:\TV\Sitcoms\WKRP in Cincinnati\WKRP in Cincinnati - Season 3\WKRP_S3E53_Bah, Humbug.mpg)