Actuator Control with Basic Switches

The easiest way to get up and running to control a linear actuator is by using a DPDT rocker switch. 

There are different rocker switches out there, make sure you have a DPDT rocker switch.  One way to check is to see how many connectors or posts there are on the switch.  A DPDT rocker switch should have 6 polee, best to have three positions so that middle is off, and you have up and down (or in and out)

There are two "common" posts or connectors in the middle of the DPDT rocker switch, and then two on either side of the "common"/middle connectors. 

When the switch is in the middle the common posts are not internally connected to anything.

When the switch is pushed up the common posts connect to the top posts.

When the switch is pushed down the common posts connect to the bottom posts.

You can also use a SPDT rocker switch (3 poles), but you'll need to incorporate relays in order to get the reversing polarity.  Some people use this method because it allows more flexibility in terms of switch selection.

While it is recomended to use 3 position switches, if all you need to do is extend or retract the actuator and not stop anywhere in between you can use 2 position switches (on/off).  This really depends on how you envision the installation of linear actuators to be used.