Found it and zapped it. Weren't that many Level 38 ghosts after all
Zapping it won't remove it from your game, but it does mean no one else will find it.
Happily, MOST of those upgrades are meaningless on a Relic Wraith (only AI summoners get the special "simulated upgrade" bonuses for things like Enemy Lure, a player's ghost is assumed to already contain the benefits of the real version from when it was alive), so assuming nothing else is weird about it it should be killable or at least avoidable I hope.
Thanks again for the report.