Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] Y
Setting up shim-signed (1.18~16.04.1+0.8-0ubuntu2) ...
Installing for x86_64-efi platform.
grub-install: error: cannot find EFI directory.
dpkg: error processing package shim-signed (--configure):
 subprocess installed post-installation script returned error exit status 1
E: Sub-process /usr/bin/dpkg returned an error code (1)