Funny Riddles

Question: Who is reading this question now?

Question: Light hides me and darkness kills me.

What am I?

Question: Walk on the living, they don't even mumble.
But walk on the dead, they mutter and grumble.

What are they?

Question: after Lindsay got grounded, why did nobody see her in her room?

Question: You bury me when I'm alive,
and dig me up only when I die.

What am I?