What's happening if I let somebody who help me to remodel the house and stay there until the job done ( because they have no trasportation ). Should I be worried about the " squatter law " ? I live in Texas.
Thanks.

After 10 to 20 years if they are still there, you may have to worry.

They are a renter at this point, a tenant, even if not paying any money

They are exchanging labor for rent.

Worry, yes normally when you help someone out, you will end up having to evict them in court.

You need to put this agreement in writing so there is no misunderstanding

Do you plan on allowing them to live there for the next 20 years or so?

If not, then no. Get their residence in writing and then if they don't leave, evict them like you would any other tenant.