Interesting, so the most radioactive things here at my house (only slightly above background, not terribly radioactive):
1. Granite countertop (this is a known thing)
2. Night lights (apparently, tritium in there to make them glow)
3. Smoke detectors (bit o'radioactivity in there)
4. Rebar in the garden (hmmmmmmmmmmmm... apparently some radioactivity in the stream, this is where it's shown up in massive contamination events in the past, i.e Ciudad Juarez and the radioactive Taiwanese apartments).
5. Maybe (tough to tell) -- some of the newer drywall. Only slightly more active against it, not a lot.
What provides far more clicking was standing out in the sun. LOL