Good Riddles

Question: A Florida man is running down a hall with a piece of paper. The lights flicker and he falls to the ground in tears.

What happened?

Question: How can you make the following true by adding a single line: .9 = 1.

Note: ≠ is not the answer.

Question: Poke your fingers in my eyes and I will open wide my jaws. Linen cloth, quills, or paper, my greedy lust devours them all.

What am I?

Question: You have a flashlight that takes 2 working batteries. You have 8 batteries but only 4 of them work.

What is the fewest number of pairs you need to test to guarantee you can get the flashlight on?

Question: I'm made up of 12 completely different letters but you can type me with just 1, what am I?