Populate Lightswitch field from Frontend Entry Form
The Lightswitch field is a simple boolean/tinyint column, with a 0/1 value. For this to work, you want to do something like this:

&lt;input type="checkbox" name="fields[gistDraft]" value="1" {% if entry.gistDraft %} checked="checked"{% endif %} /&gt;


If you are sending the value some other way than a checkbox (the lightswitch field is a hidden checkbox), make sure that gistDraft has a value of 0 (off) or 1 (on).