[[WMG: Sheridan is [[DeadAllAlong quite literally]] TheGhost]]
Yep, just like in ''WhosAfraidOfVirginiaWoolf'', the apparently miserable couple whose long marriage [[NoAccountingForTaste no-one can understand]] is entirely founded on their mutual denial of the loss of the one good thing they ever had. Although that doesn't explain why they imagine him to be an AmbiguouslyGay, profligate wastrel...
* Granted, it would present a challenge for a ghost to use the telephone.
* Well, in the Swedish novel ''The Dung-beetle Flies at Dusk'' the kindly old lady who has periodically been phoning up the protagonists with helpful if slightly cryptic hints turns out to have been DeadAllAlong...