Part of an alarm?

Boaty

Painters are outside stripping the house of its paint using a powerwasher, I went out and when I came back there was a awful noise coming from a box above the pir sensor it sounded like the crackle of gunfire.

Is the box part of the alarm or something else?

John Kelly of

yes that is the internal siren for the alarm

Boaty

Thanks, Must be an electrical fault.
Is it connected to the outside alarm siren?

John Kelly of

yes it is wired in with the strobe light probably, or you might have a tamper on the external siren which triggered the alarm what does it say at the keypad?

Boaty

No fault on the keypad, tryed to pry off the cover of the box, alarm went off.

Turned it off, noise still going on even, its less frequent now tho.

John Kelly of

there is a screw under the rectangular thing at the front, open it up and disconnect the red wire. He must have done something outside to the external siren which is causing that because they are linked.

Boaty

Turns out that water was getting in and shorting the circuit.
All it needed was to dry out