I am currently renting the first floor of a two-family home in NJ that is under foreclosure. My roommate and I never signed a lease and are on a month-to-month agreement with the landlord. If the foreclosure goes through will I get evicted? If so, how much notice will I be given to vacate the property? Also, would it help if I had a lease signed ASAP?

If it's a bank foreclosure lease or no lease you'd be out at the end of the month. The bank will most likely not bother with an eviction , they will just tell you your month to month option ends in 30 days so be out.

Actually Federal law allows you 90 days from the date of Foreclosure before you have to move out. There is a sticky note at the top of this forum that discusses this issue.

Also, you seem to have a misunderstanding about what evictions are. An eviction is a legal process in which a court orders a tenant to vacate or be physically removed. The ONLY time a tenant gets evicted is when they refuse to vacate but the deadline given by the landlord. Before a landlord can go to court they have to give the tenant a legal notice to vacate.