If you are still in need of an apartment for the school year, I would highly recommend searching on Milwaukee's Craigslist using keywords such as "MSOE", "Juneau", "Downtown", "East Side", "Lower East Side", "53202", "Brady", "Prospect", "Farwell", "Marshall", "Cass", or "Downtown Milwaukee".
If you are in the area, I would also highly recommend coming down to the MSOE area and taking a walk throughout the neighborhoods. There are many apartments within the area that do not list their apartments online or they are really hard to find. Many of the apartments in the downtown neighborhood post phone numbers and open house dates in front of their building! Also, many open houses happen on Sunday from 12 - 4pm, so that might be a good time to check some apartments out and take a stroll throughout the neighborhood.
Here are a couple of sites that I came across in my search to find an apartment: