From Pathfinder Society Scenario #3-19: Mean Streets of Shadow Absalom, which isn't enabled.

Shadow Spears (7-8)

HAZARD 7

Stealth +20 (trained)

Description Invisible runes are concealed within an elaborate light-woven floor mosaic.

Disable DC 27 Thievery (trained) to remove pieces from the mosaic without triggering the magic or Dispel Magic (4th rank; counteract DC 23) to counteract the rune

Barrage of Spears (arcane, illusion, shadow)

Trigger A creature walks upon the mosaic.

Effect The trap shoots a fusillade of shadow-wreathed spears out of the walls, making a Strike against each creature in area A1. Creatures who take damage from the spears must succeed at a DC 25 Will save or become Doomed 1 as the spears tear off part of their shadow.

Melee Shadow Spear +22, Damage 2d10+5 piercing plus 1d6 cold

Pathfinder Society Scenario #3-19: Mean Streets of Shadow AbsalomOGL