How do I get rid of musty smells?

Here are a few tips: https://www.cleanipedia.com/gb/in-the-home/get-rid-musty-smell-home.html

This is a good article https://www.onegoodthingbyjillee.com/7-ways-to-get-rid-of-musty-smells/

keep the dehumidifier on constantly. You will see the smell will disappear. It may take months for the smell to dissipate but it should work. AND keeping water out!! You might have to fix any issues with your gutters and adding some drainage tiles in your yard underground to carry water away from your house so you don't get any flood waters coming in which will give all the musty moldy smells.

Cis: you first must find the source of the musty smell. ...maybe look for a small water leak, etc. I have found that plain charcoal works well... just put in a netted bag and tuck in an inconspiculous place.

An open container of baking soda or white vinegar, kept in an unobtrusive place (for example, on top of your kitchen cupboards), can help absorb musty smells and clear the air. Experts also recommend FreshWave or DampRid, two all-natural substances that absorb smells and trap excess moisture in the air.

1. Identify the source of the odor: Musty smells can come from mold or mildew, spoiled food, laundry, or shower stalls, etc.
2. Clean thoroughly: Deep cleaning carpets, sweeping, mopping, and vacuuming can help remove musty smells

use baking soda or vinegar to clean with, purchase a dehumidifier, or consider hiring a contractor to come and investigate.