Tara:
A lot of people have given good advice as to go about gaining new members.
Back in 1982 my local fraternity was down to five members and some how they managed to keep the house and the fraternity going. There are many drawbacks, prior to my time, I've heard stories of not getting any pledges, sometimes a few semesters in a row.
What I would do:
Contact alumni, contact alumni like crazy. There are always those out there that might be out of the loop due to careers or family, but if they hear that their org is in danger of going under, and/or losing their house, they will come, trust me they will come.
Ask the alumni for donations, in a case such as this, I'd be wiling to bet many would be all for it.
Maybe get a few alumni to help out in your rush, get an alumni advisor to supervise everything and help out, so to speak.
Advertise like madness, posters, flyers, have mixers, exchanges, whatever needs to be done.
Losing your house isn't the end of the world, three years after we went local, we lost our house, but a few years later we got it back. I agree that the house is a big part of the organization, but it doesn't make up the organization. The sister/brotherhood that comes from the org is what really counts. GLO's lose houses quite a bit, they get replaced, it's something material, something that can not be compared to the friendships and bonds made by being a part of a glo.
If you would like, I can get you some contact information from a local sorority here on my campus that was down to eight members just a year ago, and now they are thriving to over 40! They did it, and I can refer you to them and they could probably give you a few great ideas. You can pm me or email me here:
bdunday@hotmail.com
Regards,
damasa