Name of movie where woman intentionally drowns to become a ghost
 

I remember watching this partly horror movie where a woman intentionally drowns herself to become a ghost, and then traverses around in what looks to be a hotel. It was overall a good movie but I can't remember the title and I don't feel like searching the internet too much with these keywords, haha. Thought some of you might have seen it

Fairly recent?

All i can think is shymalan's lady in the water

Sounds a bit like Peter Jackson's horror-comedy The Frighteners (1996), only it wasn't a woman. Michael J. Fox intentionally becomes a ghost (by freezing to death) and then pursues the bad guys into an abandoned mental hospital, which resembles a hotel. Here's a trailer:

https://www.youtube.com/watch?v=0yqhND5i05M

It could also be Dark Water (2005), starring Jennifer Connelly. I only saw this once and don't remember the exact plot, but it's got a few of the clues you mentioned: female lead, ghosts, drowning, and an apartment building (which could resemble a hotel). Here's the trailer:

https://www.youtube.com/watch?v=JcpJVEp047Q