Unwanted Alarm Siren Chirp when using GE Outdoor Smart Switch

I installed a 12V DC megaphone style siren in my attic and am using a GE Outdoor Smart Switch to activate when my alarm goes off, but I’ve run into an unexpected problem: the GE switch provides a constant 3.5-4V through the outlet, which apparently is just enough voltage to I guess charge up the brick to give a quick “pop” or “chirp” sound every 20-30 seconds.

Can anyone think of a way to solve this?

You could use a smart switch or wall plug designed for LED lights? Perhaps use a Mimolite instead?

that does seem like a lot of leakage. I’d use a different plugin module. They don’t all have that issue.