Not U.S. representatives (Congressmen). no. So Ted Bellowthon had to be elected. How vacancies of senators are filled is left up to each state to decide. Pew Research had a nice article on it last month.
This is how I think it happened: after Lois was killed during her re-election run, her brother Ted ran for her vacant seat that November and somehow won, despite the scandal involving Lois’ campaign funds. (Note: a governor is not allowed to appoint a replacement congressman, as they sometimes are in a particular state, depending on that state’s law.) Tracy-time runs slower than ours, so there may or may not be a new election cycle occurring.
Not one for the doll? LOL j/k