listRouter.delete('/:id',
    function(req, res) {
        req.list = list;
        req.list.remove(function(err){
            if (err)
                res.status(500).send(err);
            else
                res.redirect('/')
        });
});

<form method="DELETE" action="/:id">
      <button type="submit">Delete</button>
</form>

{
message: "Cast to ObjectId failed for value ":id" at path "_id"",
name: "CastError",
kind: "ObjectId",
value: ":id",
path: "_id"
}

<a class="btn btn-raised btn-danger" href="/admin/dashboard/detele/<%= data.userId %>">Delete</a></td>
<!-- The href needs to point at a link where data.userId is shown. Hence you need the = after <% for ejs to show the variable. -->

app.get('/admin/dashboard/detele/:id', users.deleteUser);

exports.deleteUser = function(req, res) {

    users.findOneAndRemove({
        userId: req.params.id
    }, function(err, user) {

        if (err) throw err;

        console.log("Success");

    });

    res.redirect('/admin/dashboard');

}

var skema = new mongo.Schema({

    name: String,
    email: String,
    password: String,
    date: {
        type: Date,
        default: Date.now
    },
    admin: Boolean
});


var users = mongo.model('accounts', skema);