3 hole outlet on ungrounded line

[Ed Melo]

I have seen some older houses where some of the outlets have been replaced with 3 hole outlets although the line going to them do not have a ground wire.

Is the only good solution to this problem replacement of the wiring?

Would you replace ALL the ungrounded wiring ? I'm sure this could be expensive but is it safe to leave the ungrounded wiring in place?

[Jon Holdman]

The ground bar and the neutral bar should be tied together in the main service panel, and should be connected both to the neutral service wire from the electric company and to an earth ground. You're right, Ryan, that its just a longer route to the same place. The point is to create a separate route. In a subpanel, such as in a garage, the ground and neutral busbars would not be tied together. Rather, each should have a separate connection back to the main service panel.

Jon