If been working for this hotel for 4 years and they fired me only because they want to hire someone to work cheaper. Do they have to evict me?

Normally your home is based on part of the pay, once you no longer work there, you will owe the normal pay for that room.

Is there a rental or employment contract in writing ?

But they can evict for non payment. If it is a hotel room or an attached apartment ? It may fall under the rules of hotel rooms.