What can I do about a musty smell?

Where is the musty smell? A room? Basement, closet?

Ditto where is the odor?

A musty smell usually implies moisture - so eliminate the moisture, you might have to remove walls, carpet, or other things depending on where the musty smell is coming from. More info would be helpful.

here are some helpful answers: http://www.hometalk.com/diy/clean/house/q-get-rid-of-musty-smell-26958553

You probably should run a dehumidifier from spring through fall, 24 hrs. a day. You do need to find the source of the moisture and start from there.

Is it a musty smell or a moldy smell? Sometimes a bowl of white vinegar in the offending might take care of it.

Place large humidifier buckets in all rooms. You can buy them at Lowe's& Home Depot for $10. I keep them in my closets too.