sorry, yeah, i dunno why i said VCC instead of GND. (that's why the flashing is reversed)
Doesn't matter though, it proves that the flash rate is perfect for a solenoid.
First you need to find a small solenoid that will run on the voltage you have available, 12V, 5V etc.. Small ones draw 0.5 - 2A, so check your power supply can handle that.
If you have, for example, 12V which is regulated to 5V to power the MCU you should use a 12V solenoid powered from your 12V.
If you cant find any solenoids you may be able to dismantle any
large relay you have in your junk box and remove the switch contacts. Then bend the contact arm so it hits the bell. It wont hit with as much force as a solenoid but it will work if the bell is large.
Now you need a "N channel logic level MOSFET".
Something in TO220 packaging will usually have plenty of power for a solenoid, get one that can handle over 40V and over 10A (most will).
(Post some part numbers you have, or can get at your local electronics store, and we can confirm if they will work.)
Two resistors, 2000 ohm and 220 ohm should work fine.
One diode. (for a small solenoid a generic 1N400X diode will work. If the solenoid is large use a larger 1N540X diode, (the X number doesn't matter)
Wire it up like this