linda,
Two-prong outlets are not inherently dangerous. Most appliances and lamps that you're going to use in a house are double-insulated and use two-prong plugs. No need in most cases for a three-prong outlet. But Dspark is right, if have an appliance or tool with a three-prong cord, you need a three-prong outlet. The adapters that let you plug a 3-prong plug into a 2-prong outlet are dangerous.
If in your day-to-day routine, any circuit breakers trip or fuses blow, then get an electrician to upgrade the circuit that's inadequate. And that might mean upgrading the fusebox or breaker panel. But not necessarily.
And do have the outlets in the kitchen and bathroom replaced with GFIs, THese do not need a ground wire to work. The GFIs will provide a margin of safety against a malfunctioning appliance or cord.
Good luck with the housse.
