What motivates Penelope to test Odysseus' identity

Well, she thought he was dead, he was gone for so many years, and she had to wait for him and decline the proposals from many princes and wealthy man who were impressed by her beauty, but who also wanted to become kings instead of Odysseus. Since she wasn't sure that this was truly him who returned, she wanted to test him so that she doesn't marry a fake guy pretending to be her husband.