I very briefly looked into this when I was refurbishing a house[1], and didn't see anything that wasn't ludicrously expensive, a scam, or both. Is there even a

I very briefly looked into this when I was refurbishing a house[1], and didn't see anything that wasn't ludicrously expensive, a scam, or both. Is there even a practical way of doing this? We've actually got a wire mesh in most of the walls due to the building materials used, but you can still pick up a (fairly weak) signal outside, mobile phones work, and windows defeat it (connection possible at >100m with generic hardware if you have line of sight through a window). [1] Just to reduce interference from external WiFi, mostly as a curiosity