You put double-sided tape under that relay (K1), right? A tie-wrap would be better.
For some reason, I had thought the Sensor would have two independent relay outputs, not a single common output with N/C and N/O contacts. Still, quite useful as-is.
Are there any components under the relay? (Seems not, but tough to tell from the photo.)
Also, the soldering doesn't look too great on all the relay leads. Be sure the relay leads are tinned (or at least fluxed) after lead-bending but prior to mounting on the board.
What is MAG1? A reed relay?
Ah, I see that HC174! My guess is you are using it as a latch to permit the processor to sleep more. But that doesn't make sense, because most MCUs have latching outputs and interrupting inputs. Hmmm... Level shifting?
The inductor (B1) is physically larger than I thought it would be. Is that due to high current (few turns of thick wire) or high inductance (many turns of fine wire)? Either way, it wouldn't make sense for use in a switching supply, so I suppose it must be an isolation choke for the radio. Which, if true, surprises me there'd be that much noise present.
Lunch time is over. Time to get back to work.