I do that kind of stuff too although it really is wrong. Keeping everything in the correct plug format serves to protect the guy down the road that doesn't know what was done. Simply labeling that a 120 Volt plug is really wired for 240 Volts (because it'll work) is dangerous, especially if the label comes off and/or you don't remember what you did a year ago. I get tempted to skip an adapter and connect wires as needed, but refrain when I think about what could happen if someone didn't know and ruined some equipment or worse, got injured (or dead even, no BS).
It is an adapter that Hydro Farm sells available through any dealer that sells their products. It is item #BAASR or #BAASP depending on the reflector brand. Go to HydroFarm.com. Top right put the BAAS x in the search box and check out which one you need. Then go to Amazon(.com) and search that product number again. Someone should be offering it there and probably for a lot less than the Hydro store. The following link will take you to the BAASR. It is: http://www.hydrofarm.com/search.php?zoom_query=baasr&zoom_and=1&zoom_sort=0&zoom_per_page=10
Ooops, You'll need the BAASP (I think); here's that link: http://www.hydrofarm.com/search.php?zoom_query=baasp&submit=Submit&zoom_per_page=10&zoom_and=1&zoom_sort=0