A standard lens cap isn't ideal .
Most of the covers on these Minolta point and shoots cameras also incorporate a shutter lock .
When you wind the film on , as you tend to do by habit after taking a shot , the shutter button is ready to be pressed again . No on or off switch .
So put the camera in your bag or pocket , and it'll take a picture as the button gets pressed .
You'll also be draining the battery as the AF is engaged .
The 3d printed item linked to engages the shutter lock to prevent accidentally taking a shot .
A regular lens cap doesn't.