It's been almost six years since the original release of Stardew Valley, and the indie farming RPG has only grown since then. Arguably the most important update that the game has received since launch is Stardew Valley 1.5, which introduced a massive array of new content and quests.
One of the more unusual items that released with Stardew Valley 1.5 is 
Ectoplasm , a translucent green material that can only be found by killing ghosts. Ectoplasm is one of the few items in Stardew Valley that only has a single use, and that's to complete a Special Order quest that the Wizard offers, called "A Curious Substance."
Where to find Ectoplasm in Stardew Valley
At the beginning of Fall on their first year in Stardew Valley, players will unlock the special orders board in front of Mayor Lewis' house. The board offers large gathering quests with valuable and often unique rewards. One of the quests on offer is "A Curious Substance," which is posted by the Wizard. To complete the quest, players will need to gather a single batch of Ectoplasm and bring it to the Wizard on time.
Ectoplasm can only be found by defeating Ghosts, and has a 9.5% chance to be dropped. Players will first encounter standard Ghosts on Floor 51 of the Mines, and they have a chance to spawn on each floor from there until Floor 79. This is probably the easiest place to find the Ectoplasm for the "A Curious Substance" quest, as these Ghosts are the weakest of their kind in the game.
There are also Carbon Ghosts and Putrid Ghosts that can appear in Skull Cavern or the dangerous version of the Mines, respectively. All three variations can drop Ectoplasm.
Ghost-Hunting Tips for Stardew Valley
Ghosts are one of the trickier monsters in Stardew Valley, due to their ability to pass through walls and dodge back after each hit. Ghosts will begin floating toward a player as soon as they arrive at a new floor of the Mines or Skull Cavern. Although they can pass through obstacles, their flying speed is slower than bats, so it may take some time for them to arrive.
Ghosts have high HP and damage output, but are easy to hit due to their slow speed. Unfortunately, Ghosts will slide back a long way each time they're hit, and it'll take a few seconds for them to come in range again. This can be particularly annoying when fighting other enemies as well, and makes the Ghosts very time-consuming to kill. The best strategy for dealing with Ghosts in Stardew Valley is to use a slow, heavy-hitting weapon, giving them fewer chances to retreat and attack again.
Stardew Valley is out now for PC, Mobile, PS4, Xbox One, and Switch.
