function CheckCollision(x1, y1, w1, h1, x2, y2, w2, h2)
  if (x1 >= x2) and (x1 <= (x2 + w2 - 1)) and (y1 >= y2) and (y1 <= (y2 + h2 - 1)) then
    return true
  end
  return false
end
testObj = { x = 22, y = 3, w = 3, h = 1 }
function clear()
  term.clear()
  term.setCursorPos(1,1)
end
function draw()
  clear()
  term.setCursorPos(testObj.x, testObj.y)
  for i = 1, testObj.w do
    for i = 1, testObj.h do
      write("#")
    end
  end
end

draw()
while true do
  e, x, y = os.pullEvent("click")
  if e then
    print("X: ", x, " Y: ", y)
    if CheckCollision(x, y, 1, 1, testObj.x, testObj.y, testObj.w, testObj.h) then -- MouseX, MouseY, 1,1    
      term.setCursorPos(1,1)
      print("True")
      sleep(.3)
      draw()
    end
  end
end

As you can see, it detects the mouse click within the area.