What's a completely mundane object you could build an entire short story around

[SkyHunter]

A parking ticket left on a windshield for three weeks, nobody claiming the car, and the story is really about the neighbors slowly inventing an entire life for whoever owns it

[alwaysPatrick19]

A single key that doesn't fit any lock in the house, and the story follows someone quietly trying every door in the neighborhood before finally learning whose house it actually belongs to

[Patrick_82]

An unclaimed umbrella in a lost and found bin for over a year, and the story is about the person who works there slowly becoming attached to a stranger they've never met

[Certified]

A single sock with no match, and the story follows it backward through every owner it's ever had before ending up forgotten in a specific drawer

[RayOfLight99]

A house key left under a mat that nobody's used in years, and the story follows the new owners slowly discovering exactly why the previous family never came back for it

[Slate Leopard]

A voicemail nobody's deleted for years, the story follows different family members each listening to it during a crisis and hearing something slightly different each time

[MegaNathan60]

A receipt for a meal for two found in an old coat pocket, and the story imagines who those two people actually were and what happened after that dinner

[Ellie_28]

A half finished crossword puzzle found in a library book, and the story imagines the two strangers who unknowingly kept passing the same book back and forth completing it together