This instructable will show you how to make a 2 min secret door on mcpe.
Step 1: The Wall
Make a simple wall with a one block wide hole in it.
Step 2: Trapdoors
Place trapdoor flat, one for each block high, then open them so they are flush with one wall.
Step 3: Paintings
Place paintings on the walls around the hole until the hole is covered and you are done. I Hope you enjoy.