Unlawful Detainer applies to persons occupying a dwelling unit as a guest of the person in lawful possession ( the owner or rightful tenant ). The permission to stay may be freely revoked and you can demand that such person move out at any time. Unfortunately, the police may not be willing to assist you in removing the unwanted guest. The police will call it a "civil matter," meaning that you will have to get a court order to remove the person. The police may also tell you to file an eviction. This is wrong as evictions only apply where there is a landlord-tenant relationship between the parties. The correct cause of action is an "uinlawful detainer."
Unlawful detainer also applies to trespassers who broke into a dwelling unit. You may of course try to get the police to remove the trespasser. If they have been there long enough or have any claim of a right to be there, you may have to file an unlawful detainer.
Unlawful detainer involves a law suit filed in County Court by the person in rightful possession seeking the recovery of possession of the rental unit and / or money damages and costs. You may recover the fair rental value of the unit, and possible double that if the court finds the refusal to surrender possession "willful." There is no provision for the award of attorneys fees. Florida Statues Chapter 82.04 governs unlawful detainers. Summary procedure applies.
The Florida Bar / Florida Supreme Court have not approved any standardized forms for unlawful detainers so you will have to hire an attorney.
The cost and time frame for unlawful detainers is the same as evictions: 3 weeks and $850.00 for one occupant, $57.00 each additional occupant.