The Tampa Bay Times recently featured an article detailing the closure of a city building due to mold contamination. The Madeira Beach building was more than 60 years old and had been flooded several times over the years.
The message here is that any Florida building can have unhealthy mold issues.
The most common causes are water incursion, and heating and cooling system (HVAC) issues. Water incursion can be due to flooding, broken pipes and roof leaks. HVAC issues include leaks in the air handler/duct system and compressor/air handler mismatch. The latter situation occurs when the BTU capacity of the compressor is too high for the system. This leads to rapid cooling of the air before it can be adequately dehumidified, with resulting moist, cool air leading to mold growth in the system.
One good resource to investigate possible indoor mold issues is via the environmental specialist at the Pinellas County Health Department.