def METHOD_NAME(
    root_folder: str | Path | None = None, excluded_paths: list[str] | None = None
) -> set[str]:
    """Finds Dockerfiles"""
    file_paths: "set[str]" = set()
    if not root_folder:
        return file_paths
    for root, d_names, f_names in os.walk(root_folder):
        filter_ignored_paths(root, d_names, excluded_paths)
        filter_ignored_paths(root, f_names, excluded_paths)
        for file in f_names:
            if is_dockerfile(file):
                file_path = os.path.join(root, file)
                file_paths.add(file_path)
    return file_paths