My client [name withheld] was able to use a pendulum to communicate with her guides, but now cannot. What is going on, and what can be done to help? Is this some force in her home causing this?

This requires some work with the Lightworker Healing Protocol to undo the negativity that has crept in over time, and this will help restore her confidence and remove the obstruction. It indeed is related to dark spirit activity, and the Protocol will take care of things nicely. It is both energy present within the environment and within her energy as well, and that is why the Protocol is ideal because it will cover both bases nicely.