Help! I don't have construction lines on my props.

So yeah, I don’t have construction lines on my props when I play singleplayer, there probably is some easy command or something I can type into the console, but I have no idea what it is, or it maybe something else. Anyway, if someone would take a minute to answer me, it would be greatly appreciated! Thanks in advance.

Are you talking about this? if so, its an Addon called SmartSnap. Just goto Gmod.org and download it.

YES! Thank you kind sir.