from typing import Optional
import random


def random_separator(min_length: int = 1, max_length: int = 3, possible_sep_chars: Optional[str] = r",./\  ") -> str:
    """
    Generates a space-padded separator of random length using a random character from possible_sep_chars
    :param min_length: minimum length of the separator
    :param max_length: maximum length of the separator
    :param possible_sep_chars: string of possible characters to use for the separator
    :return: the separator string
    """
    chars = [" "] * random.randint(min_length, max_length)
    if len(chars) > 0 and possible_sep_chars:
        sep_char = random.choice(possible_sep_chars)
        chars[random.randrange(len(chars))] = sep_char
    return ''.join(chars)