Plz help i keep hearing a noise and i cant figure out what it is?

Question

i keep hearing knocking thats either outside my house or inside the walls. ive heard it the past four nights and i cant figure out what it would be.

Answer 1

then go &see it................!!!!!!!

Answer 2

if theres a tree by your house the wind could be blowing it and it could be tapping on your house....oooorrrrr THERES TOTALLY A GHOST jk haha not funny i noe