First Gather all the components needed for this

Supplies

1. Relay
2. IN4007 Diode
3. Any NPN transistor
4. Water pump
5. Lm358 Microphone module with high output
6. micro Usb Female jack
7. Wire
8. 3mm heat shrink tube
9. Waste bottle /container
10. Waste cardboard
11. Relay Module (optional)

Step 1: Make the Circuit

You can refer to this image for making the circuit connections are quite easy

Step 2: Rearrange the Connections

Once your circuit is completed cut the pumps wire and make two holes in the waste bottle/container put the pump inside the bottle then make the wire and the pipe come out from the bottle/container

Step 3: Glue the Components and Make a Base

Here take an old cardboard price and then on that glue your components, I would recommend you to use Hot glue

Step 4: Tune Your Product

Raise your phone's volume and I would recommend you to keep it at full
There is a blue potentiometer on the sensor ,I would recommend you to tune it at max efficiency , though it will consume around 2-3 more Ma but it is worth it

Step 5: Succes!

You did it , you built your own water throwing alarm just fill the bottle/container with water , place your phone on cardboard and wait for the alarm
https://youtu.be/_HVhaJDmfzk
You can checkout my youtube video on this to view the full testing
Thanks!