I don't know based on the rulebook. The provided context explains what happens when an Investigator dies and becomes a Spirit (page 11): their player board and its associated tokens are returned to the box, and they keep all their Items, Evidence, and their standee. However, it does not specify whether Conditions or Wounds are kept, discarded, or otherwise handled during this transition. The rulebook context is insufficient to answer this question definitively. To answer, the rulebook would need to explicitly state what happens to Conditions and Wounds when an Investigator becomes a Spirit.

Source: page 11.

Source: Core Rules (pp. 10, 11, 27, 7, 8)