Android ectoplasm stuck in inventory

[Poisonousrat]

finished the wizards quest in the winter and it's now spring and the one extra ectoplasm is stuck in my inventory. not sure what exactly to do.

 

[Lomatic310]

Any fix?
It just happened to me too.

I can't drop or sell it but I can store it in a chest. The wiki said it was supposed to disappear when the quest ended.