Statistically, if you keep a loaded firearm in your house, you increase, considerably, the chances that you or your housemates/friends will be shot: that's what guns are designed for, although they're not intended for assault and homicide. 

The same can be said about opioids; if they're there, someone might decide to take them for reasons that have nothing to do with their intended use. Human beings enjoy getting stoned. They don't like pain. They make irrational choices that guns and opioids make easy to act upon

The presence of opioids and guns in so many houses, though, is not a coincidence; it's not even strictly a matter of personal choice. 

Rather they are there, in large part, as a result of rational policy choices by governments and corporations, policies that make them readily available despite the oft-demonstrated possibility of misuse.