// a function to check if the cart has product from CATEGORY and it's subcategory id
function cart_has_product_from_CATEGORY() {
    //Check to see if user has product in cart
    global $woocommerce;
    //assigns a default negative value
    $product_in_cart = false;

    // start of the loop that fetches the cart items
    foreach ( $woocommerce->cart->get_cart() as $cart_item_key => $values ) {

        $_product = $values['data'];
        $terms = get_the_terms( $_product->id, 'product_cat' );
        // second level loop search, in case some items have several categories
        if($terms){
            foreach ($terms as $term) {
                $_categoryid = $term->term_id;
					
                if (( $_categoryid === PRODUCT_CAT_ID) ) {
                    //category is in cart!
                    $product_in_cart = true;

                }
            }

        }
    }
    return $product_in_cart;
}

// add filter and function to hide method
add_filter( 'woocommerce_available_shipping_methods', 'custom_shipping_methods' , 10, 1 );
add_filter( 'woocommerce_package_rates', 'custom_shipping_methods', 100, 2 );


function custom_shipping_methods( $rates, $package ){

    // Define/replace here your correct category slug (!)
    $cat_slug = PRODUCT_CAT_SLUG;
    $prod_cat = false;

    // Going through each item in cart to see if there is anyone of your category
    foreach ( WC()->cart->get_cart() as $values ) {
        $product = $values['data'];

        // compatibility with WC +3
        $product_id = method_exists( $product, 'get_id' ) ? $product->get_id() : $product->id;

        if ( has_term( $cat_slug, 'product_cat', $product_id ) )
            $prod_cat = true;
    }

    $rates_arr = array();

    if ( $prod_cat ) {
        foreach( $rates as $rate_id => $rate ) {
            //change to live store IDs
            if ( FLAT_RATE_METHOD_ID === $rate->instance_id || FLAT_RATE_METHOD_ID  === $rate->instance_id ) {
                $rates_arr[ $rate_id ] = $rate;

            }
        }
    }
    return !empty( $rates_arr ) ? $rates_arr : $rates;

}
//Notify the client item can't be sent any other way
add_action( 'woocommerce_before_checkout_form' , 'ib_product_notices' );
add_action('woocommerce_before_cart_table','ib_product_notices');


function ib_product_notices() {
    global $woocommerce;
    if( cart_has_product_from_CATEGORY()){

        wc_print_notice( "NOTICE HERE", $notice_type = 'notice' );

    }
}