Random Spikes

I've noticed that most days I get theae spikes above background, apparently coinciding when I arrive or leave home. However I've tried searching for a sorce but find nothing. Is this just a false signal? (The alarm seems not to trigger even though the graph indicates a high enough value)

I've noticed that most days I get theae spikes above background, apparently coinciding when I arrive or leave home. However I've tried searching for a sorce but find nothing. Is this just a false signal? (The alarm seems not to trigger even though the graph indicates a high enough value)