Wooden Stake is a common Artifact — Equipment card from Innistrad (ISD), collector number 237. Current market price: $0.11 (foil $0.21), TCGplayer market prices via Scryfall.
Equipped creature gets +1/+0. Whenever equipped creature blocks or becomes blocked by a Vampire, destroy that creature. It can't be regenerated. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)