Rubber bands are currently a useless item, and often considered as junk.
Rubber bands have no use, being added purely for the purpose of clutter, creating more realism for the player when looting.
Rubber bands can be found in desks and counters.
From newitems.txt (Project Zomboid directory/media/scripts/)
Weight = 0.1,
Type = Normal,
DisplayName = Rubber Band,
Icon = RubberBand,