I just had an idea I hope will come across as a good one.
The Ideas are Preasure plates that can be invisible (crafted in another way with hard-to-get resorces)
And also making the preasure plates placeable in a roof and a wall. So if you place a preasureplate on the wall, and walk into the wall, the redstone triggers, same with the roof, if it is a 2 block high room with a preasure plate in the roof, you trigger the plate by walking underneath it, but if it is 3 blocks high, you have to jump.
Also the Invisible preasure plates should be able to put in roof and walls.