Peek in the floorboards, move the furniture, check the chink the ceiling, look behind the wallpaper. A good time to find a treasure in the folds.
And maybe just the folding, moving and looking will be treasure in itself.
An easy way to fold paper into a self-locking seed packet...someone found dozens of packets, with the plant names in elegant calligraphy, in the floorboards of a house. Drawing came to me via the local organic farm who deliver on Wednesdays...and eventually to here: https://www.bartramsgarden.org/found-floorboards-200-year-old-seed-packets/