school year internships - private equity

Question for WSO - how do students get internships during the school year?

I'm only taking 4 classes next semester, and would like to fill my free time working - and learning something new about business/the real world. I've done an IB internship at a BB, and my ideal school year internship would be something in PE.

I go to school in Pennsylvania and found a website online where I could pay $40 for a list of over 100 PE funds or hedge funds in Pennsylvania, with contact information for each. I want to start emailing them, but am frankly not sure what to say. I can't imagine any of these funds normally take interns during the school year (if they take interns at all). I'm actually not opposed to working for free if I'm learning something useful, but I'll still need to sell them on the idea of even bothering with me. Furthermore, I have class Monday through Friday, and never finish class before 2pm. I have a car, but I don't see how I could make it to an office during work hours. So I'm curious what the chances are a fund would be willing to email me work to do from school.

I know there are WSO users who have had school year internships. How did you do it? Is what I'm looking for here even possible?

Many thanks.