Movie search: A drowned young boy's vengeful spirit comes back to haunt people.

Hello all! I am looking for a movie about a young boy who inadvertanly drowned, and is now back as a ghost to torment and murder the characters. He is "summoned" or is linked to anything that relates to water, like lakes, bathtubs, sinks, etc. The protagonists become in danger whenever they get close to something like that.

ENDING:

Although I watched the movie about a decade ago, the one thing I fully remember is the ending, in which the 2 protagonists celebrate their apparent victory when a ball comes bouncing down the stairs and the boy appears at the top, saying a cliché phrase like "I'm back" or something, pointing at a possible sequel which I don't know if there ever was one.

Here's the link to the Reddit post I made in which you can find more info and the guesses that have been made: https://www.reddit.com/r/tipofmytongue/comments/owvvu8/tomtmovie_horror_movie_of_a_drowned_boys_ghost/

Thank you in advance for trying to solve this.