MQTT n8n Power Meter Integration

I have a power-meter sensor that already speaks MQTT and I want its readings flowing seamlessly into my self-hosted n8n instance. The goal is two-fold:

1. Real-time monitoring with threshold-based alerts so I immediately know when consumption spikes or drops.
2. Continuous data logging that I can later analyse for usage trends, costs and optimisation.

What I expect from you: configure the MQTT broker connection (either my existing Mosquitto or another you recommend), build the n8n workflow that subscribes to the sensor’s topic, parse and clean the payload, write it to a data store of your choice (InfluxDB, PostgreSQL, Google Sheets—open to suggestions), and set up alert nodes (e-mail, Telegram or Slack) that trigger on rules we define together.

Acceptance criteria
• n8n workflow saved and exported (.json) and running on my server.
• Live dashboard or log confirming messages are captured every time the sensor publishes.
• Alerts fire correctly when a test value crosses the set threshold.
• Brief hand-off note describing any environment variables and how to add more sensors later.

If you have handled MQTT integrations in n8n before, this should be straightforward; please let me know which similar projects you have completed and the tools you prefer for storage and visualisation.