They can be from the same state since no election is involved. The Constitution says that electoral college electors cannot vote for two candidates that are both from their state. So, even if both candidates were from the same state, only the electoral votes from that particular state would be involved.
If Biden is kicked out, Harris would appoint someone to VP not in the senate.... probably not from the House either.
My guess would be Susan Rice. I think that was the plan all along. Senate would be stalemated technically until VP appointment is confirmed....All Senate legislation requiring VP deciding vote would fail.....postponed most likely until both chambers confirm Harris pick. Then, we are back to where we were. All Repub Senators would need to hold firm to stall the VP selection .....not likely
Going forward, Once salacious dirt on Harris is conveniently released to the populace from the compliant press, she resigns due to family issues. Rice is now President....and picks another VP....probably a former, dirty Obama cabinet member with “ great credibility”.....probably someone who has blackmail on her shenanigans under Obama.
Also remember, all it takes is one Senator from either party to die, retire or defect to disrupt the entire power structure of the Senate. Both sides know this. Every Senator salivates at their potential power to extort from the leadership as well.
We are seeing biblical predictions play out.