After an ugly break-up, a man tries to put his life together by building a new home only to find out his virtual assistent is possessed by an vengeful spirit.

Love me some horror CucuMucu, think about the following while sharpening this logline.
1. Does this breakup involve an e.g. girlfriend, or does it have more weight like an ugly divorce? The logline will serve better with a big inciting incident. If the breakup is a minor part of the plot, one that you move past quickly and has little or no character reoccurrence later – you could skip right to the possession as your inciting incident.
2. OPINION: It will help to call your protag an “architect” who’s building his “dream SMART home” as an anchor for the virtual assistance + “rebuilding” metaphors.
3. Now that we’re getting closer to a strong inciting incident, focus on your protag and goal, we need to work on your antagonist. Since this is not one of those old haunted house stories you need a unique method of how this vengeful spirit possesses your virtual assistant. This can get cliché quick, be careful as we (audience) has seen it all – surprise us 😊.
4. You can also add stakes or the method of how he will overcome this vengeful spirit.

If you like, please elaborate on my above comments, whom he broke up with, and this vengeful spirit so I or the community can take a crack at this – got to be a reason why this spirit is so pissed right? 😉

Hope this helps, take care