after 18 years of employment got a new supervisor within the last 6mths and written up twice with last one been Final warning over minor mistakes.
Am I entitle to severance pay if fired?
I have receive a warning letter to sign, should I sign it?

It would be very difficult to terminate you without severance for performance reasons after 18 years of service. I would certainly not sign a warning letter without first speaking with one of our employment lawyers. Give us a call at the number below to set up a confidential consultation. We would be happy to help in any way we can.