Hopefully, you had someone while growing up who acted as a substitute dad: a grandfather, an uncle, or a close family friend. Your longing for this school worker to be a paternal figure is telling you that you need to re-connect with that individual from your childhood. Even if you don't live near him, you can reach out via phone calls, Skype, texts, and e-mails. He'll be flattered that you want his support, guidance, and love.
As adults, fatherless daughters can be drawn to men who possess qualities that they admire. These guys typically have attributes of an archetypal dad: strong, wise, protective, generous, experienced, responsible, and unselfish. There's something about the school worker that you esteem so you naturally want to get to know him better.
However, because this is a workplace relationship, you should only expect him to act in a professional way, not a fatherly one. While it's understandable that we fatherless daughters want to find dad substitutes, it's not fair to the men. It's not their responsibility to be paternal or to fill a void in our lives.
When I was in my teens and 20's, I unconsciously dated guys who I thought would fulfill my need for Daddy. Then, when they canceled a date, picked me up late, or poked fun at me, I became irrationally upset. Their behavior, while normal for young guys, triggered my insecurities as a fatherless daughter. It wasn't until I was in my 30's, secure in my career and having purchased a home, that I was confident enough to date men without expecting them to fill the space that my dad had left.
So, while it's beneficial to have positive male role models and mentors in your life, don't expect them to be fatherly. Instead, value them for who they are and what you can learn from them. Be aware that you're still yearning for a Daddy but don't demand these unsuspecting guys to fill that role. If you do, you'll only be setting yourself up for disappointment.