This mp3 playback module cost a whopping $1.15 on eBay!
Connect a speaker, pop in a micro-SD card, apply 5V and away it starts looped playback.
These modules would be ideal for ambient sounds in a Halloween or Christmas display.
There are spots on the PCB for switches.
You can set the volume by shorting the VOL+ or VOL- pads for at least one second.
Shorting them briefly activates the previous and next track functions.