@Matt J. take a look at my post from a couple years ago on my first house hack. https://www.biggerpockets.com/...
Here is an excerpt from that thread (page 5) that I think will help you:
I have had some inquiries on the format of letter that I used to make contact with owners of multifamily properties that I found on the auditors site. Below is a snapshot of my letter with a couple of items omitted. If you are not a real estate agent, this is not a problem! Just omit any mention of that point, but you can still mention that the seller would save $ vs listing on the market because you would be dealing direct and can essentially bypass agents (if they desire, or say you have no problem if they want to be represented for safety, they key is making them comfortable). I sent out a letter to 3/4 unit owners prior to this letter which was aimed just at duplexes. Since I didn't get any good leads from my first letter on 3/4 unit properties, I lowered my search down to 2 unit properties.
TIPS:
1. Mention you are not looking to buy and sell aka flip. Mention you want to hold it for a long time. Let them know where you found their contact information so they are not angry that their address may be out for who-knows-who to find. They will feel better knowing exactly how you were able to reach them.
2. Let them know that you filtered down a big list and still are interested in their property, this lets them know that you are seriously interested and aren't sending out thousands of letters looking to snag something at a low price.
3. Tell them you will pay a fair value, nobody wants someone who is going to lowball them.
4. Be personable, let them know what you do, that you are local, etc. You are local and not an 'out of state investor shark', this is to your advantage. Make this known.
5. At the end (if they are not interested) ask them to keep your business card or contact info in their junk drawer, you never know in 5-20 years from now if they will pull out your info and call.
6. Ask them (if they are not interested), if they know anybody else with a multifamily who is looking to sell. Generally folks who own 2-4 unit properties know others who do as well.
7. I said this before but will mention again, hand address these for a better open rate. You can print the letter and the return address sticky label, but hand print the to address. Also sign each letter in ink at the bottom near your salutation.
8. Give them multiple ways to contact you, and let them know they can do it at their convenience. Email, call, or text. I would rather text someone than call, this may make them more likely to contact you.
9. If you have your license, let them know that you will be using all official broker forms. This puts people at ease. If you are not an agent, work with a lawyer to draft documents if needed and let the seller know this. This step lets the potential seller know that you are not going to try to pull anything fast on them. It makes them more comfortable.
10. Let them know that you are trying to build a positive financial future for yourself and/or your family via rental property. Many of these folks were in the same shoes in the past, and people like to help others who are vulnerable enough to mention they are new and getting started. They will be more willing to talk if they see a past version of themselves within you. This is a step that is genuine and true but many people don't want to make themselves look like a newbie. Turn it around and use it to your advantage because this is the truth.
Hope this helps!