I have an MP3 sound chip module from Talking Products. 4.5 volt battery driven 40mA with an 8 Ohm. 0.5 Watt speaker. I briefly plugged in two 4 Ohm 3 Watt speakers and they worked (and sounded much better). As a complete electrical novice will things be OK if I connect them or am I playing with fire?
Since the module you are referring to is this one as far as I can tell as it is the only one they make.
As long as you connect your two 4 Ohm speakers in series it is perfectly safe. In parallel it is hard to tell since there are no specs on the module beyond what I have provided.
In series two 4 Ohm speakers will provide the same impedance as one 8 ohm speaker. So it will be completely safe, the wattage rating is only the max the speaker can handle, it doesn't indicate what it will pull, that is determined by its resistance and the drivers voltage (which in this case doesnt change.