We are changing the light in our 1/2 bath. There is no ground wire existing in this 50+ year old br. what sh?

no ground wire in our 50+ year old house. What should we doWe are changing the light in our 1/2 bath. There is no ground wire existing in this 50+ year old br. what sh?
Can you run a ground to the cold water pipe? If you can you can use the water pipe as a ground. It is not ideal but it is the next best thing to running a new power feed with a proper ground. The white wire in older homes used to double as the neutral and the ground. If you look in an electrical panel you will see they are often both connected to the same neutral bar. This is no longer acceptable under code. But you have to work with what you have.We are changing the light in our 1/2 bath. There is no ground wire existing in this 50+ year old br. what sh?
Lots of 50 year old homes don't have ground wires. No big deal.
Where does the feed for the light come from? Usually power from the panel goes to one outlet to the next to a light - i.e. it's all a daisy chain. Some electricians like to have separate lighting circuits from the outlet circuits while others wire up a circuit for a room or group of rooms. If this light gets its power downstream of an outlet then you could put a GFCI outlet there and run everything downstream off the ';LOAD'; terminals of the GFCI. No ground is required, GFCI measures difference in current between hot and neutral and can protect an ungrounded circuit.