Old knob and tube wiring should (needs to) be replaced. Belleville has very strict wiring codes and you have to use a "city approved" electrician. You can call the City of Belleville inspection dept and have them send you a copy of all of the requirements to "pass code" and get a list of the "city approved electricians" too.
Hi Bob, Your best bet is to contact Roger Barfield at (618) 233-6817 Ext. 264. Ask for a copy of the electrical guidelines and the city occupancy permit requirements. You can also go to their website. http://belleville.net/index.asp
Our family home was recently sold after my folks owning it for 60 years. It had upgrades in wiring years ago, but it still had some old two wire in places. Alton, Ill has a town inspection before a sale can close to be sure its up to their codes. This might be true in Belleville but a call to the building dept would let you know for sure whats ok and what's not with wiring. We had to add some GFIs in the bathrooms and add a disconnect next to the meter to pass the town inspection.