'Smile' Actors Infiltrate MLB Games to Plug New Horror Movie

A new horror movie is coming out next week, and the studio found a creative way to let people know about ... sending background actors to live baseball games, front and center.

We're talking about Paramount's latest offering, "Smile," which drops next Friday ... and amid a lot of "Don't Worry Darling" chatter, it seems the mountain execs were trying to find a way to break through the noise and stand out ... and they chose MLB broadcasts to do it.

Several marquee matchups aired on big-time TV stations Friday -- including Dodgers vs. Cardinals, Mets vs. A's and Yankees vs. Sox. In all of them, there was at least one person prominently positioned behind home plate that held a super creepy smile the entire time.

It was perhaps most notable during the Mets game, where a woman in a highlight green shirt (with the word SMILE written across) was standing and smiling awkwardly ... that is, until a security guard told her to park it.

Another guy in green was also spotted at the Dodgers game, sitting in silence and holding a creepy smile for much of the game. Some of them stood up at times, but mostly sat still and just held the pose ... completely committed to the gag.

Another man, this time in blue, was seen at the Yankees game ... and he got up occasionally -- with viewers at home certainly taking notice and noting it was freaking them out.

Unclear if there were more actors at other games, but these are the ones that people paid close attention to. Of course, this is good old-fashioned viral marketing ... and it would appear it worked, 'cause the stunt is getting some media coverage.

"Smile" is going up against Billy Eichner's rom-com, "Bros," next week ... not to mention any spillover from 'DWD' and other recent horror releases like "Barbarian" and "Pearl." Plus, "Avatar" is back in theaters, and it already seems to be doing well -- so tough competition.

Paramount's smiling through it all though, especially at the ballpark!