There are a few signs that a last will and testament may be fake:

1. The document is not properly executed: A valid will must be signed by the person making the will (also known as the testator) and witnessed by two other people who are present at the same time. If the will is not properly signed and witnessed, it may be considered invalid.
2. The testator was not of sound mind: In order for a will to be considered valid, the testator must have been of sound mind at the time they signed the will. If there is evidence that the testator was not mentally competent at the time they made the will (e.g. due to mental illness, drug or alcohol use, or undue influence), the will may be challenged.
3. The will was not found until after the testator’s death: If the will was not found until after the testator’s death, it could be considered suspicious and may be subject to challenge.
4. The will is not consistent with the testator’s previous wills or with the testator’s known wishes: If the will is significantly different from the testator’s previous wills or from what is known about the testator’s wishes, it could be considered suspect and may be subject to challenge.

If you suspect that a last will and testament is fake, it is a good idea to consult with an attorney who can review the document and advise you on your options.