def METHOD_NAME(requested_hash: str) -> Optional[str]:
    """
    Try to delete key file
    :param requested_hash: The hash to delete
    :return: The name of the deleted file or None if not found
    """
    keys_dir = CONFIG["wifi_keys_dir"]
    available_keys = os.listdir(keys_dir)
    if requested_hash not in available_keys:
        return None
    key_path = os.path.join(keys_dir, requested_hash)
    name = os.listdir(key_path)[0]
    shutil.rmtree(key_path)
    return name