I live in a 45-50 year old house. I tested all my outlets with a tester and all my outlets read open ground. All of my outlets are two prong no third hole for a grounded plug. I used a three prong adapter with my tester. Is this normal for an older home or do I have an electrical problem

Its normal for an older home, you need 3 wires and a 3 prong receptacle to be grounded. No cheap or easy fix since pulling a 3rd wire to every outlet is difficult and costly. You can install GFCI receeptacles which have a 3 prong hole but you will not be truly gorunded, just ground faulted

There may be a ground in the outlet box, but using a three wire tester on two wire outlets will automatically give an open ground result.

Need to check what type of wiring method was used.