scare the life out of (one)
To shock or frighten one very suddenly and/or severely. Hyperbolically alludes to frightening one so badly as to cause them to die. Don't sneak up on me like that, you scared the life out of me! That car accident seems to have scared the life out of Janet—she's still shaken by it.
frighten/scare the ˈlife out of somebody
frighten somebody very much: Don’t do that! You scared the life out of me creeping up on me like that!