Can I use my doorbell transformer to measure voltage for real power measurement?

[BrutusBoots]

I really should have searched first

US plug AC adapters

I only have one temperature sensor that isn’t even plugged in at the moment. I don’t think I need it anyway as I have other temperature/humidity sensors throughout the house. Other than that, I’ll just have 4 CT’s on each emonTX. If I have to run USB for power, I’m ok doing that too if necessary.