Did this ever happen on previous BB for like a party or anything or am I off my rocker in thinking that???

Nikki Grahame in BB7, the public voted her into the house next door with Mikey, Grace and lea during 2nd last week, housemates chose her to re-enter the house for the final week and was eligible to win, came 5th.

Jon Tickle BB4 went back in for last week as a guest I believe.

I don't know about the C5 era but because of this timewarp twist could happen on friday,