1, shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention or public surveillance, and shall also or only be fined;

2. If the amount is huge or there are other serious circumstances, he shall be sentenced to fixed-term imprisonment of not less than three years but not more than ten years and shall also be fined;

3. If the amount is especially huge or there are other especially serious circumstances, he shall be sentenced to fixed-term imprisonment of not less than 10 years or life imprisonment, and shall also be fined or confiscated.

Selling a house with someone else's signature will be punished by law. The signed contract may constitute contract fraud, and other corresponding contracts may constitute financial fraud and bill fraud. Signing on behalf of others is an agency act. If I don't know, I have no right to represent and I don't bear legal responsibility.

People's Republic of China (PRC) Civil Code

Article 66

If there is no agency, beyond the agency or after the termination of the agency, the principal can bear civil liability only after ratification by the principal. If the act is not ratified, the actor shall bear civil liability. Knowing that someone else has committed a civil act in my name without denying it is regarded as consent.