12v AC relay - few and far between?


Looking for a 12v AC relay - these seem to be non-existant in my desired price bracket (about £3 max each + P&P). Is this my bad or…?
Basically wanting to “read” a pre existing doorbell circuit. Thanks all


(I think I’m just going to buy a bridge rectifier)


Have you considered a voltage/current/hall sensor?


Or opto isolator?