Unknown Smell in Room

So we have a weird issue in one of my kids' rooms in our house (built around 2005). There is an odd smell coming from the room that I find hard to describe. My wife is certain it is mold, but to me it's closer to the smell of asian beetles. It's just kind of a stale smell. It has not always been there. I'm looking for ideas to check on what it could be to remedy the issue. It doesn't seem to be anything we have added to the room (furniture, etc.).

The room has a spigot on the outside wall that has a leak when opened. The brick below the spigot gets soaked. However, the smell has come on in the last few months and I have not used the spigot much in that time. We pulled up carpet in corner of room where the spigot is and don't see any sign of mold.

I have also checked the attic above the room, and do not notice the smell nor do I see signs of water/pests.

Anybody got an idea? My wife is ready to rip out the drywall to hunt for mold, but I would love to avoid that if there are other potential sources of the smell.