'Ghost' is one of the few words in English that begins GH. What's the connection between 'ghost', Caxton and some immigrants?

The connection would be "fear".

Visual morphemes. A number of English spellings are deliberately non-phonemic. For example, ed for past tense and s for plural have been consciously introduced as being more useful than phonemic spellings in these grammatical contexts. The avoidance of homographs for homophones also was a deliberate decision by Mulcaster, for example, rite, right, write, wright. Also some other interesting visual morphemes seem to have developed through unconscious motivation. For example, when Caxton had the monopoly of printing in England, he changed many g spellings into gh. "Girl", "goose", "goat", "ghost", and "ghastly" were all spelled with g before Caxton. Caxton spelled them all with gh. As more competing printing presses were introduced, the gh's reverted to g's - but a few words kept Caxton's gh, for example, ghost, ghastly, ghoul, ghetto. They all seem to have some connection with the emotion of fear.

Nice try mozart but any link with fear is coincidental.The connection is to do with some people who Caxton employed.

'When Caxton first set up the new business in London he brought with him Flemish workers from the Low Countries, where he himself had learned it. Now the Flemish used the spelling 'gh' to represent their own voiced guttural continuant, a long-rolled-out sound (y) unlike our English (g). English had no such sound at the time, but the employees in Caxton's shop were accustomed to combining the two letters, and continued to do so in setting up certain English words. In words like 'ghost' and 'ghastly' it has persisted, one of the many mute witnesses to orthographical conservatism.'

http://www.uefap.com/reading/exercise/ess2/schlauch.htm

"Ghetto" is a calc from Italian. The h after the g indicates a /g/ before e and i. Otherwise it would be an affricate.

Juan, could you rephrase what you just wrote in a language that we dummies speak? I have no idea what you just wrote.

LOL. OK. "Ghetto" is a loan word from Italian, and the spelling was retained. In Italian if you want a "hard g" sound before an e and an i, you follow the g with h. Otherwise it's pronounced like jet. Lo capisci adesso?

Much better Juan. The first time, no entendì ni...er... mother.

Yes , Jenny , that's the reason for 'ghost'. Caxton had some employees who thought that 'gh' was the way to reproduce the sound. That was how they did it back home.