This feels like an extremely thicky question to me. But I can’t work it out.
I want to use treasure chests, and assume the right way to do that is with an invisible switch. But if I put it on the chest then it doesn’t work, presumably because the hero never gets close enough; and if I put it next to the chest then the hero can only come at it in one direction, or may accidentally open it by walking past it. Also, he’s conspicuously half a mile away from the chest when he opens it.
I’m assuming that you’re using non-collision invisible actors, that ones that look like a square that a hero can walk over. Have you tried using the collision invisible actor, the one that looks a bit like a bookstand? If you place it straight over the chest, the hero should be able to interact with it from any angle by bumping into the chest.
Let me know if this helps and good luck on your game!