I changed a fan with a light in a old house there were 2 wires coming into the box from different ends of a none grounded box, both black to find out the hot wire I used my volt tester ,using the box but was not grounded so I pluged an extension cord into a receptile that had 3 wire romex and found the hot wire by using one end of tester on one wire the other in the ground of the extension cord and found the hot one... does that sound OK? Is that type set up OK? With no groung?

Thanks in advance

Perfect. Good troubleshooting method. No ground is OK for a ceiling fixture.

Thanks tkrussell!