Anderson was an individual of unknown gender.
According to a story once told by the Ghost Host, a book by Anderson was among the volumes in the bookcase in architects Mr Davis and Mr Coats's study as they got to work designing Gracey Manor. A book by Sklar was stacked unstably on top of it.
Behind the scenes
Sklar's name appears in the 2005 story Blueprint for Murder. Like all the names of authors in the story, it is an allusion to one of the Imagineers responsible for designing The Haunted Mansion in the real world — in this case, Ken Anderson.
Notably, in 2011, an epitaph was added in Walt Disney World's Haunted Mansion also paying tribute to Ken Anderson, as it referred to “Our Friend Ken”. However, there exists no in-universe link between the two glimpsed names.