https://www.aeroportodinapoli.it/en_GB/info-and-services/swab-covid-19
↑ナポリ空港のサイトです。参考までに。

RapidはNGでMolecularはOKらしいです。

ちなみにメールで問い合わせしたら以下の回答もらいました。

The result of the PCR molecular tests are available in 12/24/36 hours
If the sampling is made not after 10:00 from Monday to Saturday, the results are ready circa at 6:00 pm of the same day
If the swab is done after 10:00 of every weekday except Sunday, the result will be ready by 18:00 of the next day
If you do the test on Saturday, after 10:00 am and the whole day of Sunday, you receive the results the next Monday starting from 2:00 pm