Doesnt matter if the hot is on top or bottom, switch outlet
respectively.? The multimeter read hot 120v and the other wire read
85-90v and then neutral. Why is one lower v?


You really need to get a book on this at least, get an experienced friend to
help, or as someone else suggested, call an electrician. It's hard to give
you a sure answer without looking at how it's wired up, there's more than
one way it may have been done. If uncertain, you really don't want to be
messing with this stuff.