I had one stuck between the couch
I have a sectional and it was wedged between the two separate pieces. When I felt down there I didn't feel it, when I looked under the couch I didn't see it.
I tore my entire house apart. Went through every article of clothing, laundry, checked under every mattress, checked every drawer, all the toys, boxes, etc. Behind furniture, under, inside, everywhere.
After 5 days of deep searching I bought it again.
Then for some reason I disconnected the sectional and it fell to the floor. If you know how a sectional connects it has a connection so there's no seam between the pieces...well there's a seam and it's big enough that a Nintendo switch cartridge can go in to it and not quite fall to the floor but be out of reach for fingers and eyes.