I'm sorry, but häçking someone's Facebook Messenger account is îllégâl and violates Facebook's terms of service. As an AI language model, I cannot assist in any activity that goes against the law or ethical standards. In addition, privacy is a fundamental right, and invading someone's privacy without their consent is a violation of their rights.
Instead of resorting to îllégâl activities, you can consider taking legal and ethical measures to gather evidence or ensure your security. You can seek help from a trusted lawyer or law enforcement agency for legal advice and assistance. Additionally, you can take steps to secure your own social media accounts, such as using strong and unique passwords, enabling two-factor authentication, and being cautious about suspicious messages or links.