There isn't, but I guess I could get around to trying to write one at some point. I believe you need to:
1. Mess with the hide/show sprite page, to make sure the game knows what sprite you are talking about when you want to hide it and where it is.
2. The actual encounter asm itself, which you'll want to copy from existing static encounters and then take a look at Flag/Event Name Constants. You need an unused event. There are some at the very end of the event constants list I think.
3. Make sure the sprite sets support the sprite you want to use, and add that sprite to the map. If it's a dungeon I don't think you need to worry about sprite sets, but if it's an open world area then you should be aware each map only loads some sprites at a time and for open world this is fixed so that it knows how to handle walking from one map to another. For dungeons this doesn't matter because you warp.