You’ll want to post more info about your set up, (ie. C++ VS blueprints, and what type of UObjects your dealing with).
But mostly all actors and components have a boolean field for visibility and all you will need to do is set it up such that when you play your sound, you set the visibility of the Actor or Component resenting your spooky character. Set Hidden also works, its just the reverse of set visible. I would also recommend that you set the actor/components collisions to None, otherwise your player could bump into your invisible character.
Try googling, “UE4 SetVisiblity” or “UE4 SetHidden” and you will quickly find what you need.
Please note that although the forum is a great place to get help, but this question is really basic and probably best answered by just reading the documentation. In the future you should read the Docs before posting a question like this as this is UE4 basics 101.
