For the entity you want to move:
"classname" "func_train"
"speed" "#"
"target" "targetto"
Put a number in for "#" to control the speed of the object moving. It will take some trial and error to get it right for your map, but 300 is generally a good speed.
You can name "targetto" whatever you want, just make sure that one of the path_corners has a targetname of the same value.
You can place your func_train anywhere on the map depending on how you want your lighting to look; it won't affect in-game location because it will already have a specified path to follow.
To control where the func_train goes, use path_corners. Use as many as necessary.
"classname" "path_corner"
"targetname" "targetfrom"
"target" "targetto"
The value of "target" should be the same as the value of "targetname" for the next path_corner to which you want the func_train to go.
The value of "targetname" should be the same as the value of "target" on the path_corner from which the func_train will come.
The values of "target" and "targetname" can be anything you want as long as they match up with the proper path_corners.
Additional values for path_corners:
"pathtarget" "targetto" triggers an entity with a targetname that matches "targetto" to perform its action when the func_train hits the path_corner
"wait" "#" change # to the number of seconds you want the func_train to stay at the path_corner before moving on to the next. Default is 0.
