A 6-year-old boy flying alone from Philadelphia to Fort Myers was “incorrectly boarded” onto a flight to Orlando on Dec. 21, a Spirit Airlines spokesperson said Thursday. The Spirit Airlines spokesperson said that the boy was always under the care and supervision of a Spirit ream member and that the boy’s family was contacted as soon as they discovered the error. The spokesperson did not say how the mistake was made, but said that an internal investigation was underway. The boy’s grandmother, Maria Ramos, told southwest Florida TV station WINK-TV that it was the boy’s first time on a plane. “T…