In[]:=
myIndicatorFunc[a_,b_,var_]:=​​Piecewise[{​​{0,var<a},​​{1/2,var==a},​​{1,a<var<b},​​{1/2,var==b},​​{0,b<var}}]​​​​Manipulate[​​Show[​​Plot[myIndicatorFunc[-2,5,x],{x,-10,10}],​​Graphics[{PointSize[0.02],​​Point[{y,myIndicatorFunc[-2,5,y]},​​VertexColorsRed]},{x,-10,10}]],​​{y,-10,10,1/2,AnimationRate5}]
Out[]=
​
y
-10
-5
5
10
-1.0
-0.5
0.5
1.0