Ok, been tasked with building a prop bomb. It has to be housed in a project box, be loud enough to be heard in a large room with plenty of dividing walls, and activated by a toggle + button switch. It needs to be done on a budget so unfortunately no micro controllers and LCDs, keypads maybe. I was considering a loud kitchen timer, but it would have to be of a certain standard where I could remove the casing and solder before fitting in the box. Does anyone have any ideas for a device that would be ready to use, I can set a time on, and butcher? A really odd bloody question, I know.