I want to replace my kitchne light. The light I was going to buy has a metal case. I have been told that the case must be earthed. The present light on has 2 wire Red & Black with no earth. Above the kitchen is a bathroom with a tiled floor which would be impossible to lift easily to find a junction box to run new wiring to the fitting.

Must these lights have an earth wire attached or is there a way around this.

It would be good to let us know that you are not in the US or Canada.
UK?

Sorry should have said the property is in the UK

Check if there is a metal outlet box, and if so, check that is grounded (USA term for earthed).

Need to use a voltage tester one lead on live wire and other lead to metal box.

If you read voltage, then it is earthed.

If not, need to check with local codes about if and how to earth this fixture.

Most, if not all, electrical experts here are based in North America, and not familiar with UK codes.