X-ray without doing anything and just staring at a block you can x-ray with no cheats.

Put the summary of the bug you're having here

When I look at a block at its corner the corner in my screen it has x-ray

What I expected to happen was...:
to see was a normal Minecraft

What actually happened was...:
I saw mobs underground.

Steps to Reproduce:
1. dig a 7x6 hole
2. Locate a corner to the right
3. the first block to the left of the corner look at that and then but it depends

4. make sure it is day

here is picture proof