You don't need a spell with a poor kitty's whiskers. I'm sure the cat will not appreciate that at all. Their whiskers help them navigate in the dark! And do you know how vain cats are? You would upset them greatly.
One of the easiest ways to see spirits needs absolutely no "ingredients"! No spell. It is an exercise. This is how I have taught quite a few people.
Sit in a completely dark room at night with a single candle flame (or other equally dim source of light). Put the candle in a corner of the room (being sure it isn't a fire hazard) and sit with your back to it and face the center of the room. You don't need to sit close to the candle. It's only there for the purpose of light.
Sit quietly, allowing your eyes to adjust. Relax and find a spot at the opposite side of the room as your focal point. Meditate while staring at only this point, but use your peripheral vision to constantly remain aware of the entire perimeter of the room around you. Don't move your eyes or head. Keep focused on that point, whatever it is.
Don't see anything? Well, you always have to consider that you may just not have any spirits in that room! Try on another night, particularly one when you sense someone in the room with you, but do not see them. Heck, even tell them to stick around so you can try to see them. They may pose for you! LOL
You can also use this to see auras. So if you are still having no luck with having house spirits, you can check out the spirit (aura) of physical living creatures. If you don't have a friend or animal that's willing to sit for you, try using a nice lively house plant.
Remember don't make it your focal point, that's important! Keep it in your peripheral vision. Play around with it's position/your focal point to find the best, most comfortable angle. Later on, when you consistently see in this way, you can slowly move your eyes without tensing up to bring your focus on them. It takes practice and patience. You really do have to be relaxed and meditate. Getting scared or nervous, tensing up, or glancing around quickly and paranoid isn't going to get you anywhere. Even while seeing, you have to maintain a calm state.
Once you start seeing, you don't really stop. So I hope you know what you're getting yourself into. Best to know how to protect and banish so if you see anything frightening, you know how to handle it. Remember, they were there before you saw them there. But no one likes waking up to seeing uninvited guests in their bedroom. It's a little unnerving. So learn how to ward/protect first. ;P