From Pathfinder #160: Assault on Hunting Lodge Seven, which isn't enabled.

Arcane Feedback Trap

HAZARD 13

Stealth +25 (expert)

Description A spike of stone bursts from the south wall and quickly retracts.

Disable DC 33 Arcana (master) to quell the rippling stone or Dispel Magic (7th rank, counteract DC 31) to dispel the magical feedback.

AC 10

Stone Spike (arcane, earth)

Trigger A creature in area E1 casts an arcane spell or uses an arcane ability

Effect The trap makes a stone spike attack against the triggering creature. For the next 1 minute thereafter, the ripples are stronger, giving the trap a +2 circumstance bonus on stone spike Strikes during this time.

Melee Stone Spike +31, Damage 6d12+24 piercing

Pathfinder #160: Assault on Hunting Lodge SevenOGL