Number 8
The number 8 is octo in Latin, which puns with acto / acta for “acted”. Enacting hoaxes is what the spooks do all the time, so this is a hoax marker. Because octo & act are often-used Latin loanwords, it even works in modern English.
Spookery is ruling by enacting hoaxes. Spooks are actors, acting on the public stage. Latin octo “eight” punning with acto “acted” is therefore a straightforward pun. It even works in English, and can be understood by spooklings who don’t speak Latin.
Pun-wise, the 8 is thus a very good hoax marker. However, in terms of being distinct & unambiguous, all single digits are bad hoax markers, because they occur everywhere randomly. The 8 is therefore often combined with 1 or 11 to aces & eights, which works in Latin & Hebrew.
Latin octo = eight; acta, acto = acted, played, enacted
octō : eight — Latin (Wikt)
āctus; ācta; āctō : made, done, having been done; perfect passive participle of agō (“make, do”). — Latin (Wikt)
agō; āctus; āctum; āctū : do; make; act, play, perform (e.g., a role in a play) — Latin (Wikt)
āctiō : action; a doing or performing, behavior; (drama) the action, plot, series of events — Latin (Wikt)