Write a suspenseful short story about a young woman who receives a mysterious package in the mail with no return address and no indication of who sent it

Write a suspenseful short story about a young woman who receives a mysterious package in the mail with no return address and no indication of who sent it. As she begins to investigate the contents of the package, she realizes that it holds clues to a dark secret from her past that she thought she had buried long ago. With each new revelation, she becomes more and more terrified of what she might uncover and who might be watching her every move. Can she unravel the mystery before it’s too late?