H. P. Lovecraft's stories include several different, apparently independent ways that a person can become an undead creature after their own natural death (being raised from saltes, being reanimated with an injection of West's formula, using the Spanish doctor's process, etc.). Whether relating to primarily occultic or primarily medical processes, inherent to these situations is the fact that they are unusual - most people don't have the opportunity to get raised from saltes, injected with West's formula, etc. One possible exception to the rule that people only "come back" as a result of an explicit plot token process, not commonly available to most or even many people who have died, is The Outsider, in which
The main character wakes up in what he eventually discovers is the afterlife, from which he "returns" to our world and "rises" from the grave as undead. He's apparently no one special - he had a family, and a home, but wasn't particularly famous, and there's no indication that he was specifically chosen by some mad scientist or eldritch horror as his latest test subject.
Is there anything in the writings of Lovecraft or other Mythos writers that explains whether becoming Undead is standard fare for persons who have died, or whether there is a "standard" place that people "go" when they die, even if they do not become undead?
In other words, for some random person in the Mythos universe - one who isn't on Curwen's radar, one who isn't anywhere near Herbert West's victim research subject hunting grounds, etc., what happens to them when they die? Do they go to their own version of that underground castle? Do they get judged by some Elder God and get assigned to a specific afterlife? Do they simply cease to exist as an independent being unless they are specifically chosen for resurrection?