110 circuit fails, now reads 220?

I have an old house with a fuse box. A circuit for one wing of the house failed while I was vacuuming--no blown fuse, circuit just stopped working. I have isolated the problem (I think) to the pair of fuses that control that circuit. If I switch the wires for the circuit to another pair of fuses, the circuit works fine. When I reconnect the wires to that pair of fuses, I am reading 220 voltage with a tester instead of 110, and the circuit is still dead. Took the sockets out and cleaned them, no effect. anyone have any ideas? Thanks.