Cardiophobia

Felix's Room on the bed (after Lucas' cutscene)
You get one when you save Emelie (She gives it to you before leaving)
In the little garden outside Mother's Room
Inside the crack in the basement (First room to the left when entering)
Under the flower pot after finding Lucas
Hallway to the maze garden (Only when not too scared)
In the kitchen sink (Doesn't matter if its full of blood or not)

Lucas' Room
Library
Outside the stone room (Only when not too scared)
TV Room
In the small garden (Access-able after using the pick at the crack in the same room)
Marcus' Room
Paper Room (The room in the basement that has a circle puzzle on the door)