I noticed two student loans on my report that have a social number similar to mine, but is not mine. I'm not sure how to investigate, other than call up DOE. Any suggestions? I thought that the account numbers on student laons were always your social sec number, is this not the case?

Student loan account numbers are usually some combination of social and other identifying numbers.
It is not mandatory that the account number and social match.

However, if you see a loan that doesn't seem like one of your's check the NSLDS and see what school is reporting it, then verify that you attended and during that academic period.

Just to add an example -

If your social is 111-11-111 and the student loan reports as 111-11-223901 and a second one as 111-11-223902, that is not out of the ordinary. However, if your student loans are reporting more like 112-13-223901 then you may have an issue. Again, check NSLDS ans verufy the school and term for the loans, determine if they are yours or not before trying to dispute. If the school is local and the loans are recent, you should be able to go into the FA office and get copies of the paperwork.

Thanks for the help!